Metallocenes containing aryl-substituted indenyl derivatives as ligands, process for their preparation, and their use as catalysts

ABSTRACT

Metallocenes containing aryl-substituted indenyl derivatives as ligands, process for their preparation, and their use as catalysts.  
     A very effective catalyst system for the polymerization or copolymerization of olefins comprises a cocatalyst, preferably an aluninoxane or a supported aluminoxane, and a metallocene of the formula I  
                 
 
     in which, in the preferred form, M 1  is Zr or Ef, R 1  and R 2  are halogen or alkyl, R 3  is alkyl, R 4  to R 12  are alkyl or hydrogen and R 13  is a (substituted) alkylene or heteroatom bridge.  
     The metallocenes, in particular the zirconocenes, produce polymers of very high molecular weight, in the case of prochiral monomers polymers of very high molecular weight, very high stereotacticity and very high melting point, at high catalyst activities in the industrially particularly interesting temperature range between 50 and 80° C. In addition, reactor deposits are avoided by means of supported catalyst systems.

DESCRIPTION

[0001] Metallocenes containing aryl-substituted indenyl derivatives asligands, process for their preparation, and their use as catalysts.

[0002] The invention relates to novel metallocenes containingaryl-substituted indenyl derivatives as ligands which can be used veryadvantageously as catalysts components in the preparation of polyolefinsof high isotacticity, narrow molecular-weight distribution and very highmolecular weight.

[0003] Polyolefins of high molecular weight are of particular importancefor the production of films, sheets or large hollow articles ormoldings, such as, for example, pipes.

[0004] The literature discloses the preparation of polyolefins usingsoluble metallocene compounds in combination with aluminoxanes or othercocatalysts which, due to their Lewis acidity, are able to convert theneutral metallocene into a cation and stabilize it.

[0005] Soluble metallocene compounds based on bis(cyclopentadienyl)dialkyl zirconium or bis (cyclopentadienyl) zirconium dihalide incombination with oligomeric aluminoxanes are capable of polymerizingethylene in good activity and propylene in moderate activity.Polyethylene having a narrow molecular-weight distribution and moderatemolecular weight is obtained. The polypropylene prepared in this way isatactic and has a very low molecular weight.

[0006] The preparation of isotactic polypropylene is achieved with theaid of ethylenebis(4,5,6,7-tetrahydro-1-indenyl)zirconium dichloridetogether with an aluminoxane in a suspension polymerization (cf. EP 185918). The polymer has a narrow molecular-weight distribution. Aparticular disadvantage of this process is that, at industriallyrelevant polymerization temperatures, only polymers having a very lowmolecular weight can be prepared.

[0007] A special preactivation method for the metallocene using analuminoxane has also been proposed, resulting in a significant increasein the activity of the catalyst system and in a considerable improvementin the grain morphology of the polymer (cf. DE 37 26 067). However, thepreactivation hardly increases the molecular weight at all.

[0008] Also known are catalysts based on ethylenebisindenylhafniumdichloride and ethylenebis(4,5,6,7-tetrahydro-1-indenyl)hafniumdichloride and methylaluminoxane, by means of which relativelyhigh-molecular-weight polypropylenes can be prepared by suspensionpolymerization (cf. J. Am. Chem. Soc. (1987), 109, 6544). However, thegrain morphology of the polymers produced in this way under industriallyrelevant polymerization conditions is unsatisfactory, and the activityof the catalyst systems employed is comparatively low. Together with thehigh catalysts costs, inexpensive polymerization using these systems isthus impossible.

[0009] A significant increase in the molecular weight has been achievedby using metallocenes in which the aromatic π-ligands fixed by a bridgecarry substituents in the 2-position (cf. DE 40 35 886) or in the 2- and4-position (cf. DE 41 28 238).

[0010] A further increase in the molecular weight has been achieved byusing aromatic n-ligands containing substituents in the 2-, 4- and6-position (cf. DE 41 39 596) and aromatic a-ligands of the4,5-benzoindenyl type (cf. DE 41 39 595).

[0011] The last-mentioned metallocenes containing said substituents arealready very effective in this respect at the polymerization temperatureof 70° C. Nevertheless, the molecular weights which can be achieved atthe industrially optimum polymerization temperature of 70° C. are stilltoo low for many industrial applications, such as, for example, thepreparation of polymers for pipes and large hollow articles, and inparticular fibers.

[0012] Under the constraints of inexpensive large-scale production,polymerizations must be carried out at the highest possible reactiontemperature, since the heat of reaction produced at relatively highpolymerization temperatures can be dissipated using little coolingmedium. The cooling-water circuit can therefore be made significantlysmaller.

[0013] A disadvantage which frequently occurs in soluble (homogeneous)metallocene/methylaluminoxane catalyst systems in processes in which thepolymer is formed as a solid is the formation of thick deposits onreactor walls and stirrer. These deposits are formed by agglomeration ofthe polymer particles if the metallocene, or aluminoxane, or both, arein the form of a solution in the suspension medium. Deposits of thistype in the reactor systems must be removed regularly, since theyrapidly achieve considerable thicknesses, have high strength and hinderheat exchange with the cooling medium.

[0014] It is therefore advantageous to employ metallocenes in supportedform. An efficient and simple process for supporting metallocenes whichcan be employed universally in all polymerization processes has beenproposed (cf. EP 92 107331.8).

[0015] A further disadvantage in the case of stereospecificpolymerization of prochiral monomers, for example of propylene, usingmetallocene catalysts is the relatively low isotacticity, which resultsin low melting points in the case of isotactic polypropylene. Inparticular metallocenes containing substituents in the 2- and 4-positionand specifically rac-dimethylsilylbis (2-methyl-4-isopropylindenyl)zirconium dichloride in combination with methylaluminoxane gives, in thecase of propylene, a polymer of high isotacticity and thus high meltingpoint (cf. DE 41 28 238). Nevertheless, the melting points which can beachieved are too low at industrially relevant polymerizationtemperatures (for example 70° C.) for some industrial applications.

[0016] However, there are also industrial applications in which lowmelting points are desired.

[0017] The object was to find a process and/or a catalyst system whichproduces polymers of very high molecular weight and, in the case ofisospecific polymerization of prochiral monomers, polymers of highisotacticity in high yield. The use of a support would prevent thedisadvantages known from the prior art caused by deposit formation and ahigh proportion of fine particles. The use of hydrogen as molecularweight regulator should then enable the entire range of industriallyinteresting molecular weights to be covered by means of only a singlemetallocene.

[0018] It has been found that metallocenes containing specific indenylderivatives as ligands are suitable catalysts (catalyst components) inthe preparation of polyolefins of high molecular weight, in particularon use of prochiral monomers of isotactic polyolefins of very highmolecular weight and very high isotacticity.

[0019] Reaction of these soluble metallocenes with a supportedorganoaluminum catalyst component gives a catalyst system which requiresno additional cocatalyst for activation and completely preventsformation of reactor deposits.

[0020] The present invention therefore relates to compounds of theformula I:

[0021] in which

[0022] M¹ is a metal from group IVb, Vb or VIb of the Periodic Table,

[0023] R¹ and R² are identical or different and are a hydrogen atom, aC₁-C₁₀-alkyl group, a C₁-C₁₀-alkoxy group, a C₆-C₁₀-aryl group, aC₆-C₁₀-aryloxy group, a C₂-C₁₀-alkenyl group, a C₇-C₁₀-arylalkyl group,a C₇-C₄₀-alkylarl group, a C₈-C₄₀-arylalkenyl group, an OH group or ahalogen atom, the radicals R³ are identical or different and are ahydrogen atom, a halogen atom, a C₁-C₁₀-alkyl group, which may behalogenated, a C₆-C₁₀-aryl group, an —NR¹⁶ ₂, —SR¹⁶, —OSiR¹⁶ ₃, —SiR¹⁶ ₃or —PR¹⁶ ₂ radical, in which R¹⁶ is a halogen atom, a C₁-C₁₀-alkyl groupor a C₆-C₁₀-aryl group, R⁴ to R¹² are identical or different and are asdefined for R³, or adjacent radicals R⁴ to R¹², together with the atomsconnecting them, form one or more aromatic or aliphatic rings, or theradicals R⁵ and R⁸ or R¹², together with the atoms connecting them, forman aromatic or aliphatic ring,

[0024] R¹³ is

[0025] ═BR¹⁴, ═AIR¹⁴, —Ge—, —O—, O—S—, ═SO, ═SO₂, ═NR¹⁴, ═CO, ═PR¹⁴ or═P(O)R¹⁴, where R¹⁴ and R¹⁵ are identical or different and are ahydrogen atom, a halogen atom, a C₁-C₁₀-alkyl group, aC₁-C₁₀-fluoroalkyl group, a C₁-C₁₀-alkoxy group, a C₆-C₁₀-aryl group, aC₆-C₁₀-fluoroaryl group, a C₆-C₁₀-aryloxy group, a C₂-C₁₀-alkenyl group,a C₇-C₄₀-arylalkyl group, a C₇-C₄₀-alkylaryl group or aC₈-C₄₀-arylalkenyl group, or R¹⁴ and R¹⁵, in each case together withatoms connecting them, form one or more rings, and

[0026] M² is silicon, germanium or tin.

[0027] The present invention also relates to a process for thepreparation of an olefin polymer by polymerization or copolymerizationof an olefin of the formula R^(a)—CH═CH—R⁶, in which R^(a) and R^(b) areidentical or different and are a hydrogen atom or a hydrocarbon radicalhaving 1 to 14 carbon atoms, or R^(a) and R^(b), together with the atomsconnecting them, may form one or more rings, at a temperature of from−60 to 200° C., at a pressure from 0.5 to 100 bar, in solution, insuspension or in the gas phase, in the presence of a catalyst formedfrom a metallocene as transition-metal compound and a cocatalyst,wherein the metallocene is a compound of the formula I.

[0028] The compounds according to the invention are metallocenes of theformula I

[0029] in which M¹ is a metal from group IVb, Vb or VIb of the PeriodicTable, for example titanium, zirconium, hafnium, vanadium, niobium,tantalum, chromium, molybdenum or tungsten, preferably zirconium,hafnium or titanium.

[0030] R¹ and R² are identical or different and are a hydrogen atom, aC₁-C₁₀-, preferably C₁-C₃-alkyl group, a C₁-C₁₀-, preferablyC₁-C₃-alkoxy group, a C₆-C₁₀-, preferably C₆-C₈-aryl group, a C₆-C₁₀-,preferably C₆-C₈-aryloxy group, a C₂-C₁₀-, preferably C₂-C₄-alkenylgroup, a C₇-C₄₀-, preferably C₇-C₁₀-arylalkyl group, a C₇-C₄₀-,preferably C₇-C₁₂-alkylaryl group, a C₈-C₄₀-, preferablyC₈-C₁₂-arylalkenyl group, or a halogen atom, preferably chlorine.

[0031] The radicals R³ to R¹² are identical or different and are ahydrogen atom, a halogen atom, preferably fluorine, chlorine or bromine,a C₁-C₁₀-, preferably C₁-C₄-alkyl group, which may be halogenated, aC₆-C₁₀-, preferably C₆-C₈-aryl group, an —NR¹⁴ ₂, —SR¹⁶, —OSiR¹⁶ ₃,—SiR¹⁶ ₃ or —PR¹⁶ ₂ radical, where R¹⁶ can be a halogen atom, preferablychlorine, or a C₁-C₁₀-, preferably C₁-C₄-alkyl group or a C₆-C₁₀-,preferably C₆-C₈-aryl group.

[0032] The adjacent radicals R⁴ to R¹², together with the atomsconnecting them, can form an aromatic, preferably 6-membered aromatic oraliphatic, preferably 4-8-membered aliphatic ring.

[0033] R¹³ is

[0034] ═BR¹⁴, ═AIR¹⁴, —Ge—, —O—, —S—, ═SO, ═SO₂, ═NR¹⁴, ═CO, ═PR¹⁴ or═P(O)R¹⁴, preferably

[0035] ═BR¹⁴, ═AIR¹⁴, —Ge—, —O—, O—S—, ═SO, ═SO₂, ═NR¹⁴, ═CO, ═PR¹⁴ or═P(O)R¹⁴, where R¹⁴ and R¹⁵ are identical or different and are ahydrogen atom, a halogen atom, a C₁-C₁₀-, preferably a C₁-C₄-alkyl, inparticular a methyl group, a C₁-C₁₀-fluoroalkyl group, preferably a CF₃group, a C₆-C₁₀-, preferably C₆-C₈-aryl group, a C₆-C₁₀-fluoroarylgroup, preferably a pentafluorophenyl group, a C₁-C₁₀-, preferablyC₁-C₄-alkoxy group, in particular a methoxy group, a C₂-C₁₀-, preferablyC₂-C₄-alkenyl group, a C₇-C₄₀-, preferably C₇-C₁₀- arylalkyl group, aC₈-C₄₀-, preferably C₈-C₁₂-arylalkenyl group, a C₇-C₄₀-, preferablyC₇-C₁₂-alkylaryl group, or R¹⁴ and R¹⁵, in each case with the atomsconnecting them, form a ring.

[0036] M² is silicon, germanium or tin, preferably silicon or germanium.

[0037] For compounds of the formula I, it is preferred that

[0038] M¹ is zirconium or hafnium,

[0039] R¹ and R² are identical and are a C₁-C₃-alkyl group or a halogenatom, the radicals R³ are identical and are a C₁-C₄-alkyl group, R⁴ toR¹² are identical or different and are hydrogen or a C₁-C₄-alkyl group,

[0040] R¹³ is

[0041] where M² is silicon or germanium and R¹⁴ and R¹⁵ are identical ordifferent and a C₁-C₄-alkyl group or a C₆-C₁₀-aryl group.

[0042] Preference is furthermore given to the compounds of formula I inwhich the radicals R⁴ and R⁷ are hydrogen, and R⁵, R⁶ and R⁸ to R¹² area C₁-C₄-alkyl group or hydrogen.

[0043] Particular preference is given to compounds of the formula I inwhich M¹ is zirconium, R¹ and R² are identical and are chlorine, theradicals R³ are identical and are a C₁-C₄-alkyl group, R⁴ and R⁷ arehydrogen, R⁵, R⁶ and is R⁸ to R¹² are identical or different and are aC₁-C₄-alkyl group or hydrogen, and R¹³ is

[0044] where M² is silicon, and R¹⁴ and R¹⁵ are identical or differentand are a C₁-C₄-alkyl group or a C₆-C₁₀-aryl group.

[0045] The preparation of the metallocene I is carried out by processesknown from the literature and is shown in the reaction scheme below:

[0046] The 2-phenylbenzyl halide derivatives of the formula A arecommercially available or can be prepared by methods known from theliterature.

[0047] The conversion to the compounds of the formula B is carried outby reaction with substituted malonic esters under basic conditions, suchas, for example, in ethanolic solutions of sodium ethoxide.

[0048] The compounds of the formula B are hydrolyzed by means of alkalimetal hydroxides, such as potassium hydroxide or sodium hydroxide, andthe resultant dicarboxylic acids are decarboxylated by treatment atelevated temperature to give the compounds of formula C.

[0049] The ring closure to give the corresponding phenyl-1-indanones ofthe formula D is carried out by reaction with chlorinating reagents,such as, for example, SOCl₂, to give the corresponding acid chloridesand subsequent cyclization by means of a Friedel-Crafts catalyst in aninert solvent, such as, for example, AlCl₃ or polyphosphoric acid inmethylene chloride or CS₂.

[0050] The conversion to the 7-phenylindene derivatives of the formula Eis carried out by reduction using a hydride-transferring reagent, suchas, for example, sodium borohydride or lithium aluminum hydride orhydrogen and an appropriate catalyst in an inert solvent, such as, forexample, diethyl ether or tetrahydrofuran, to give the correspondingalcohols and dehydration of the alcohols under acidic conditions, suchas, for example, p-toluene-sulfonic acid or an aqueous mineral acid, orby reaction with dehydrating substances, such as magnesium sulfate,anhydrous copper sulfate or molecular sieve.

[0051] The preparation of the ligand systems of the formula G and theconversion to the bridged, chiral metallocenes of the formula E and theisolation of the desired racemic form are known in principle. To thisend, the phenylindene derivative of the formula E is deprotonated usinga strong base, such as, for example, butyllithium or potassium hydridein an inert solvent, and is reacted with a reagent of the formula F togive the ligand system of the formula G. This is subsequentlydeproteinated by means of two equivalents of a strong base, such as, forexample butyllithium or potassium hydride in an inert solvent, and isreacted with the appropriate metal tetrahalide, such as, for example,zirconium tetrachloride, in a suitable solvent. Suitable solvents arealiphatic or aromatic solvents, such as, for example, hexane or toluene,ethereal solvents, such as, for example, tetrahydrofuran or diethylether, or halogenated hydrocarbons, such as, for example, methylenechloride or halogenated aromatic hydrocarbons, such as, for example,o-dichlorobenzene. Separation of the racemic and meso forms is effectedby extraction or recrystallization using suitable solvents.

[0052] The derivatization to give the metallocenes of the formula I canbe carried out, for example, by reaction with alkylating agents, such asmethyllithium.

[0053] Metallocenes I according to the invention are highly activecatalyst components for the polymerization of olefins. The chiralmetallocenes are preferably employed as racemates. However, it is alsopossible to use the pure enantiomers in the (+) or (−) form. The pureenantiomers allow an optically active polymer to be prepared. However,the meso form of the metallocenes should be removed, since thepolymerization-active center (the metal atom) in these compounds is nolonger chiral due to the mirror symmetry at the central metal atom andit is therefore not possible to produce a highly isotactic polymer. Ifthe meso form is not removed, atactic polymer is formed in addition toisotactic polymer. For certain applications, for example soft moldings,this may be entirely desirable.

[0054] According to the invention, the cocatalyst used is preferably analuminoxane of the formula IIa for the linear type and/or of the formulaIIb for the cyclic type

[0055] where, in the formulae IIa and IIb, the radicals R¹⁷ may beidentical or different and are a C₁-C₆-alkyl group, a C₆-C¹⁸-aryl group,benzyl or hydrogen, and p is an integer from 2 to 50, preferably 10 to35.

[0056] Radicals R¹⁷ are preferably identical and are preferably methyl,isobutyl, phenyl or benzyl, particularly preferably methyl.

[0057] If the radicals R¹⁷ are different, they are preferably methyl andhydrogen or alternatively methyl and isobutyl, where hydrogen orisobutyl is preferably present to the extent of 0.01-40% (number ofradicals R¹⁷).

[0058] The aluminoxane can be prepared in various ways by knownprocesses. One of the methods is, for example, to react an aluminumhydrocarbon compound and/or a hydridoaluminum hydrocarbon compound withwater (in gas, solid, liquid or bound form—for example as water ofcrystallization) in an inert solvent (such as, for example toluene). Inorder to prepare an aluminoxane containing different radicals R¹⁷, twodifferent trialkylaluminum compounds, for example, according to thedesired composition are reacted with water.

[0059] The precise structure of the aluminoxanes IIa and Ilb is unknown.

[0060] Irrespective of the preparation method, all aluminoxane solutionshave in common a varying content of unreacted aluminum startingcompound, which is in free form or as an adduct.

[0061] It is possible to reactivate metallocene by means of aluminoxaneof the formula IIa and/or IIb before use in the polymerization reaction.This significantly increases the polymerization activity and improvesthe grain morphology. Reactivation of the transition-metal compound iscarried out in solution. The metallocene is preferably dissolved in asolution of the aluminoxane in an inert hydrocarbon. Suitable inerthydrocarbons are aliphatic or aromatic hydrocarbons. Toluene ispreferred.

[0062] The concentration of the aluminoxane in the solution is in therange from about 1% by weight to the saturation limit, preferably from 5to 30% by weight, in each case based on the total amount of solution.The metallocene can be employed in the same concentration, but ispreferably employed in an amount of from 10⁻⁴ to 1 mol per mol ofaluminoxane. The preactivation is carried out for from 5 minutes to 60hours, preferably for from 5 to 60 minutes. The temperature is −78 to100° C., preferably from 0 to 70° C.

[0063] The metallocene can be used to carry out a prepolymerization,preferably using the (or one of the) olefin(s) employed in thepolymerization.

[0064] The metallocene can also be applied to a support. Suitablesupport materials are, for example, silica gels, aluminum oxides, solidaluminoxane or other inorganic support materials, such as, for example,magnesium chloride. Another suitable support material is a polyolefinpowder in finely divided form.

[0065] It is preferred to apply the cocatalyst, i.e. the organoaluminumcompound, to a support, such as, for example, silica gels, aluminumoxides, solid aluminoxane, other inorganic support materials oralternatively a polyolefin powder in finely divided form, and then toreact it with the metallocene.

[0066] Inorganic supports which can be employed are oxides produced byflame pyrolysis by combustion of element halides in an oxyhydrogenflame, or can be prepared as silica gels in certain particle sizedistributions and particle shapes.

[0067] The preparation of the supported cocatalyst can be carried out,for example, as described in EP 92 107 331.8 in the following way in anexplosion-proofed stainless-steel reactor with a 60 bar pump system,with inert-gas supply, temperature control by jacket cooling and secondcooling circuit via a heat exchanger on the forced-circulation system.The pump system aspirates the reactor contents via a connection in thereactor bottom and forces them into a mixer and back into the reactorthrough a rising line via a heat exchanger. The mixture is designed sothat the feed contains a narrowed tube cross section, where an increasedflow rate is produced and in whose turbulence zone a narrow feed line isinstalled axially and against the flow direction and which can be fed—incycles—in each case with a defined amount of water under 40 bar ofargon. The reaction is monitored via a sampler in the pump circuit.

[0068] In principle, however, other reactors are also suitable.

[0069] In the above-described reactor having a volume of 16 dm³, 5 dm³of decane are introduced under inert conditions. 0.5 dm³ (=5.2 mol) oftrimethylaluminum are added at 25° C. 250 g of silica gel SD 3216-30(Grace AG) which had previously been dried at 120° C. in an argonfluidised bed are then metered into the reactor through a solids funneland homogeneously distributed with the aid of the stirrer and the pumpsystem. A total amount of 76.5 g of water is introduced to the reactorin portions of 0.1 cm³ every 15 seconds over the course of 3.25 hours.The pressure, caused by argon and the evolved gases, is kept constant at10 bar by a pressure-regulation valve. When all the water has beenintroduced, the pump system is switched off and the stirring iscontinued for a further 5 hours at 25° C.

[0070] The supported cocatalyst prepared in this way is employed as a10% strength suspension in n-decane. The aluminum content is 1.06 mmolof Al per cm³ of suspension. The isolated solid contains 31% by weightof aluminum, and the suspension medium contains 0.1% by weight ofaluminum.

[0071] Further ways of preparing a supported cocatalyst are described inEP 92 107331.8.

[0072] The metallocene according to the invention is then applied to thesupported cocatalyst by stirring the dissolved metallocene with thesupported cocatalyst. The solvent is removed and replaced by ahydrocarbon in which both the cocatalyst and the metallocene areinsoluble.

[0073] The reaction to give the supported catalyst system is carried outat a temperature of from −20 to +120° C., preferably at from 0 to 100°C., particularly preferably at from 15 to 40° C. The metallocene isreacted with the supported cocatalyst by combining the cocatalyst as afrom 1 to 40% strength by weight suspension, preferably with a from 5 to20% strength by weight suspension, in an aliphatic, inert suspensionmedium, such as n-decane, hexane, heptane or diesel oil, with a solutionof the metallocene in an inert solvent, such as toluene, hexane, heptaneor dichloromethane, or with the finely ground solid of the metallocene.Conversely, it is also possible to react a solution of the metallocenewith the solid of the cocatalyst.

[0074] The reaction is carried out by vigorous mixing, for example bystirring at a molar Al/M¹ ratio of from 100/1 to 10,000/1, preferablyfrom 100/1 to 3,000/1, and for a reaction time of from 5 to 120 minutes,preferably from 10 to 60 minutes, particularly preferably from 10 to 30minutes, under inert conditions.

[0075] During the reaction time for the preparation of the supportedcatalyst system, in particular on use of metallocenes according to theinvention having absorption maxima in the visible region, changes in thecolor of the reaction mixture occur which can be used to monitor theprogress of the reaction.

[0076] When the reaction time is complete, the supernatant solution isseparated off, for example by filtration or decanting. The solid whichremains is washed from 1 to 5 times with an inert suspension medium,such as toluene, n-decane, hexane, diesel oil or dichloromethane, inorder to remove soluble constituents in the catalyst formed, inparticular to remove unreacted and thus soluble metallocene.

[0077] The supported catalyst system prepared in this way can be driedin vacuo as a powder or resuspended with adhering solvent and meteredinto the polymerization system as a suspension in one of theabovementioned inert suspension media.

[0078] According to the invention, compounds of the formulae R¹⁸_(x)NH_(4-x)BR¹⁹ ₄, R¹⁸ _(x)PH_(4-x)BR¹⁹ ₄, R¹⁸ ₃CBR¹⁹ ₄ and BR¹⁹ ₃ canbe used as suitable cocatalysts in place of or in addition to analuminoxane. In these formulae, x is a number from 1 to 4, preferably 3,the radicals R¹⁸ are identical or different, preferably identical, andare C₁-C₁₀-alkyl, C₆-C₁₈-aryl or 2 radicals R¹⁸, together with the atomconnecting them, form a ring, the radicals R¹⁹ are identical ordifferent, preferably identical, and are C₆-C₁₈-aryl, which may besubstituted by alkyl, haloalkyl or fluorine. In particular, R¹⁸ isethyl, propyl, butyl or phenyl and R¹⁹, phenyl, pentafluorophenyl,3,5-bistrifluoromethylphenyl, mesityl, xylyl or tolyl (cf. EP 277 003,EP 277 004 and EP 426 638).

[0079] If the abovementioned cocatalysts are used, the actual (active)polymerization catalyst comprises the product of the reaction of themetallocene and one of said compounds. For this reason, this reactionproduct is preferably prepared in advance outside the polymerizationreactor in a separate step using a suitable solvent.

[0080] In principle, the cocatalyst can be, according to the invention,any compound which, due to its Lewis acidity, is able to convert theneutral metallocene into a cation and stabilize the latter (“labilecoordination”). In addition, the cocatalyst or the anion formedtherefrom should not undergo any further reactions with the metallocenecation formed (cf. EP 427 697).

[0081] In order to remove catalyst poisons present in the olefin,purification using an alkylaluminum compound, for exampletrimethylaluminum or triethylaluminum, is advantageous. Thispurification can be carried out either in the polymerization systemitself, or the olefin is brought into contact with the Al compoundbefore introduction into the polymerization system and is subsequentlyremoved again.

[0082] The polymerization or copolymerization is carried out in a knownmanner in solution, in suspension or in the gas phase, continuously orbatchwise, in one or more steps, at a temperature of from −60 to 200°C., preferably from 30 to 80° C., particularly preferably from 50 to 80°C. The polymerization or copolymerization is carried out using olefinsof the formula R⁴—CH═CH—R^(b). In this formula, R^(a) and R^(b) areidentical or different and are a hydrogen atom or an alkyl radicalhaving 1 to 14 carbon atoms. However, R^(a) and R^(b) may alternativelyform a ring together with the carbon atoms connecting them. Examples ofsuch olefins are ethylene, propylene, 1-butene, 1-hexene,4-methyl-1-pentene, 1-octene, norbornene and norbornadiene. Inparticular, propylene and ethylene are polymerized.

[0083] If necessary, hydrogen is added as a molecular-weight regulatorand/or in order to increase the activity. The overall pressurepolymerization system is from 0.5 to 100 bar. Polymerization ispreferably carried out in the industrially particularly interestingpressure range from 5 to 64 bar.

[0084] The metallocene is used in the polymerization in a concentration,based on the transition metal, of from 10⁻³ to 10⁻⁴ mol, preferably from10⁻⁴ to 10⁻⁷ mol, of transition metal per dm³ of solvent or per dm³ ofreactor volume. The aluminoxane is used in a concentration of from 10⁻⁵to 10⁻¹ mol. preferably from 10⁻⁴ to 10⁻² mol, per dm³ of solvent or perdm³ of reactor volume. The other cocatalysts mentioned are used in anapproximately equimolar amount with respect to the metallocene. Inprinciple, however, higher concentrations are also possible.

[0085] If the polymerization is carried out as a suspension or solutionpolymerization, an inert solvent which is customary for the Zieglerlow-pressure process is used. For example, the polymerization is carriedout in an aliphatic or cycloaliphatic hydrocarbon; examples which may bementioned are propane, butane, hexane, heptane, isooctane, cyclohexaneand methylcyclohexane. It is furthermore possible to use a benzine orhydrogenated diesel oil fraction. Toluene can also be used. Thepolymerization is preferably carried out in the liquid monomer.

[0086] If inert solvents are used, the monomers are metered in in gas orliquid form.

[0087] The polymerization can have any desired duration, since thecatalyst system to be used according to the invention exhibits only aslight time-dependent drop in polymerization activity.

[0088] Before addition of the catalyst, in particular of the supportedcatalyst system (comprising a metallocene according to the invention anda supported cocatalyst or a metallocene according to the invention andan organoaluminum compound on a polyolefin powder in finely dividedform), another alkylaluminum compound, such as, for example,trimethylaluminum, triethylaluminum, triisobutylaluminum,trioctylaluminum or isoprenylaluminum, may additionally be introducedinto the reactor in order to render the polymerization system inert (forexample to remove catalyst poisons present in the olefin). This compoundis added to the polymerization system in a concentration of from 100 to0,01 mmol of Al per kg of reactor contents. Preference is given totriisobutylaluminum and triethylaluminum in a concentration of from 10to 0.1 mmol of Al per kg of reactor contents. This allows the molarAl/M¹ ratio to be selected at a low level in the synthesis of asupported catalyst system.

[0089] In principle, however, the use of further substances forcatalysis of the polymerization reaction is unnecessary, i.e. thesystems according to the invention can be used as the only catalysts forthe polymerization of olefins.

[0090] The process according to the invention is distinguished by thefact that the metallocenes described give polymers of very highmolecular weight, in the case of prochiral monomers very high molecularweight and very high stereo-tacticity, with high catalyst activities inthe industrially particularly interesting temperature range from 50 to80° C.

[0091] In particular, the zirconocenes according to the invention aredistinguished by the fact that, in the case of stereospecificpolymerization of prochiral olefins, for example polypropylene, polymersof high isotacticity are obtained.

[0092] In particular in the case of isospecific polymerization ofpropylene, isotactic polypropylene having long isotactic sequencelengths and high melting point are obtained.

[0093] In addition, the catalyst systems supported according to theinvention prevent reactor deposits.

[0094] The examples below serve to illustrate the invention in greaterdetail.

[0095] All glass equipment was dried by heating in vacuo and was flushedwith argon. All operations were carried out in Schlenk vessels withexclusion of moisture and oxygen. The solvents used were in each casefreshly distilled over Na/K alloy under argon and stored in Schlenkvessels.

[0096] The determination of the Al/CH₃ ratio in the aluminoxane wascarried out by decomposition of the sample using H₂SO₄ and determinationof the volume of the resultant hydrolysis gases under standardconditions and by complexometric titration of the aluminum in thesample, then dissolved, by the Schwarzenbach method.

[0097] For Example Nos. 3 to 5 with the supported aluminum compound(methylaluminoxane on silica gel), referred to below as “MAO on SiO₂”,an approximately 10% strength by weight suspension in n-decane wasprepared, containing, according to aluminum determination, 60 mg ofAl/cm³.

[0098] For Examples 26 to 30 with the supported aluminum compound(methylaluminoxane on silica gel SD 3216-30/Grace), referred to below as“FMAO on SiO₂”, a solvent-free powder was used containing 20% by weightof aluminum in the solid.

[0099] Toluene-soluble methylaluminoxane was employed as a 10% strengthby weight toluene solution for the examples for suspensionpolymerization and for bulk polymerization with unsupported metalloceneand contained, according to aluminum determination, 36 mg of Al/cm³. Themean degree of oligomerization, according to freezing point depressionin benzene, was n=20. For the toluene-soluble methylaluminoxane, anAl:CH₃ ratio of 1:1.55 was determined.

[0100] The following abbreviations are used

[0101] VI=viscosity index in cm³/g

[0102] M_(w)=weight average molecular weight in g/mol (determined by gelpermeation chromatography)

[0103] M_(w)/M_(n)=molecular weight dispersity

[0104] M.p.=melting point in IC (determined by DSC, heating/cooling rate20° C./min)

[0105] II=Isotactic index (II=mm+1.2 mr, determined by ¹³C-NMRspectroscopy)

[0106] MFI 230/5=meltflow index, measured in accordance with DIN 53735,in dg/min

[0107] BD=polymer bulk density in g/dm³.

[0108] Synthesis of the metallocenes I used in the polymerizationexamples (the starting materials employed are commercially available):

[0109] A. rac-Dimethylsilylbis(2-methyl-4-phenylindenyl)zirconiumdichloride (5)

[0110] 1. (±)-2-(2-phenylbenzyl)propionic acid (1).

[0111] 48.6 g (0.279 mol) of diethylmethyl malonate were added dropwiseat room temperature to 6.5 g (0.285 mol) of sodium in 160 cm³ ofH₂O-free EtOE. 70.4 g (0.285 mol) of 2-phenylbenzyl bromide in 20 cm³ ofH₂O-free EtOR were subsequently added dropwise, the batch was refluxedfor 3 hours. The solvent was stripped off, and 200 cm³ of H₂O were addedto the residue. The organic phase was separated off, and the aqueousphase was saturated with NaCl and extracted twice with 200 cm³ of Et₂Oin each case. The organic phase combined with the extracts was dried(MgSo₄).

[0112] The residue remaining after the solvent had been stripped off wastaken up in 500 cm³ of EtOH and 50 cm³ of H₂O, and 56 g (1 mol) of KOHwere added. The reaction mixture was refluxed for 4 hours. The solventwas stripped off in vacuo, the residue was taken up in 500 cm³ of H₂O,and the solution was acidified to pH 1 by means of concentrated aqueousHCl. The precipitate which deposited was filtered off with suction andheated for 30 minutes at 250° C. in a bulb tube with vigorous foaming,giving 58.3 g (85%) of 1 as a viscous oil.

[0113]¹H-NMR (100 MHz, CDCl₃): 11.7 (s, 1H, COOH), 7.1-7.5 (m, 9H, arom.H) 2.3-3.2 (m, 3H, CH and CH₂), 0.9 (d, 3H, CH₃).

[0114] 2. (±)-2-Methyl-4-phenylindan-1-one (2)

[0115] A solution of 58 g (0.242 mol) of 1 in 60 cm³ (0.83 mol) ofthionyl chloride was stirred at room temperature for 18 hours. Excessthionyl chloride was removed at 10 mbar, and the oily residue was freedfrom adhering residues of thionyl chloride by repeated dissolution in100 cm³ of toluene in each case and stripping off in vacuo.

[0116] The acid chloride was taken up in 150 cm³ of toluene and addeddropwise at 10° C. to a suspension of 48 g (0.363 mol) of AlCl₃ in 400cm³ of toluene. When the addition was complete, the mixture was refluxedfor a further 3 hours. The reaction mixture was poured into 500 g of iceand acidified to pH 1 by means of concentrated aqueous HCl. The organicphase was separated off, the aqueous phase was then extracted threetimes with 100 cm³ of Et₂O in each case. The combined organic phaseswere washed with saturated aqueous NaHCO₃ solution and saturated aqueousNaCl solution and then dried (MgSO₄), giving 50.4 g (93%) of 2, whichwas reacted further without further purification.

[0117]¹H-NMR (100 MHz, CDCl₃): 7.2-7.8 (m, 8H, arom. H), 3.3 (dd, 1H,β-H), 2.5-2.9 (m, 2H, α- and β-H), 1.3 (d, 3H, CH₃).

[0118] 3. 2-Methyl-7-phenylindene (3)

[0119] 50 g (0.226 mmol) of 2 were dissolved in 450 cm³ of THF/MeOH(2:1), and 12.8 g (0.34 mol) of sodium borohydride were added inportions at 0° C. with stirring. The reaction mixture was stirred for afurther 18 hours and poured into ice, concentrated HCl was added to pH 1and the mixture was extracted a number of times with Et₂O. The combinedorganic phases were washed with saturated aqueous NaHCO₃ solution andNaCl solution and then dried (MgSO₄). The solvent was removed in vacuo,and the crude product, without further purification, was taken up in 1dm³ of toluene, 2 g of p-toluene sulfonic acid were added, and themixture was refluxed for 2 hours. The reaction mixture was washed with200 cm³ of saturated aqueous NaHCO₃ solution, and the solvent wasremoved in vacuo. The crude product was purified by filtration through500 g of silica gel (hexane/CH₂Cl₂), giving 42 g (90%) of 3 as acolorless oil.

[0120]¹H-NMR (100 MHz, CDCl₃): 7.0-7.6 (m, 8H, arom. H), 6.5 (m, 1H,H-C(3)), 3.4 (s, 2H, CH₂), 2.1 (s, 3H, CH₃).

[0121] 4. Dimethylbis(2-methyl-4-phenylindenyl)silane (4)

[0122] 29 cm³ (73 mmol) of a 2.5 M solution of butyllithium in hexanewere added at room temperature under argon to a solution of 15 g (72.7mmol) of 3 in 200 cm³ of H₂O- and O₂-free toluene and 10 cm³ of H₂O- andO₂-free THF and heated at 80° C. for 1 hour. The batch was subsequentlycooled to 0° C., and 4.7 g (36.4 mmol) of dimethyldichlorosilane wereadded. The mixture was heated at 80° C. for 1 hour and subsequentlypoured into 100 cm³ of H₂O. The mixture was extracted a number of timeswith Et₂O, and the combined organic phases were dried (MgSO₄). The crudeproduct remaining after the solvent had been stripped off waschromatographed on 300 g of silica gel (hexane/CH₂Cl₂), giving 12.0 g(70%) of 4.

[0123]¹H-NMR (100 MHz, CDCl₃): 7.10-7.70 (m, 16H, arom. H), 6.80 (m, 2H,H-C(3)), 3.80 (8, 2H, H—C(1)), 2.20 (m, 6H, CH₃) −0.20 (m, 6H, CH₃Si).

[0124] 5. rac-Dimethylsilylbis(2-methyl-4-phenylindenyl)zirconiumdichloride (5)

[0125] 10.6 cm³ (26 mmol) of a 2.5 M solution of butyllithium in hexanewere added at room temperature under argon to a solution of 6.0 g (12.9mmol) of 4 in 100 cm³ of H₂O- and O₂-free toluene, and the mixture wasrefluxed for 3 hours. The suspension of the dilithio salt wassubsequently cooled to −25° C., and 3.2 g (13.6 mmol) of zirconiumtetrachloride were added. The batch was warmed to room temperature overthe course of 1 hour, stirred for a further hour and then filteredthrough a G3 frit. The residue was extracted with 50 cm³ of toluene, andthe combined filtrates were freed from solvent under an oil-pump vacuum,giving 9.0 g of the metallocene in the form of a yellow powder as amixture of the racemic and meso forms in the ratio 1:1. Pure racemate(5) was isolated by stirring the crude mixture a number of times with 20cm³ of methylene chlorine in each case, the racemate remaining as ayellow crystal powder and the meso form being washed out. 2.74 g (33%)of the pure racemate were obtained.

[0126]¹H-NMR (300 MHz, CDCl₃): 7.0-7.7 (m, 16H, arom. H), 6.9 (s, 2H,H—C(3)), 2.2 (s, 6H, CH₃), 1.3 (m, 6H, CH₃Si). Molecular weight : 626M⁺, correct decomposition pattern.

EXAMPLE Brac-Methylphenylsilanediylbis-(2-methyl-4-phenylindenyl)zirconiumdichloride (7)

[0127] 1. Methylphenylbis-(2-methyl-4-phenylindenyl)silane (6)

[0128] 21 ml (52 mmol) of a 2.5 M solution of butyllithium in hexanewere added at room temperature under argon to a solution of 10.3 g (50mmol) of 3 in 90 ml of H₂O- and O₂-free toluene and 10 ml of H₂O- andO₂-free THF. The mixture was heated at 80° C. for 1 hour andsubsequently cooled to 0° C. 4.8 g (25 mmol) ofmethylphenyldichlorosilane were added, and stirring was continuedovernight at room temperature. The precipitated LiCl was separated offby filtration, and the crude product remaining after the solvent hadbeen stripped off in vacuo was chromatographed on 300 g of silica gel(hexane/CH₂Cl₂ 9:1), giving 4.6 g (35%) of 6.

[0129]¹H-NMR (100 MHz, CDCl₃): 7.0-7.8 (m, 16H, arom. H), 6.9 (m, 2H,H—C(3)), 3.9 (m, 2H, H—C(1)), 2.3 (m, 6H, CH₃), −0.1 (s, 3H, CH₃Si).

[0130] 2.rac-Methylphenylsilanediylbis(2-methyl-4-phenylindenyl)zirconiumdichloride (7)

[0131] 3.6 ml (8.9 mmol) of a 2.5 M solution of butyllithium in hexanewere added at room temperature under argon to 2.3 g (4.4 mmol) of 6 in25 ml Of H₂O- and O₂-free toluene, and the mixture was heated at 80° C.for 3 hours. The suspension of the dilithio salt was subsequently cooledto −30° C., and 1.1 g (4.5 mmol) of zirconium tetrachloride were added.The mixture was warmed to room temperature over the course of 1 hour andstirred for a further 1 hour. After filtration through a G3 frit, thesolvent was removed from the filtrate, and the residue was crystallizedfrom 10 ml of methylene chloride, giving 0.2 g of the racemic form of 7as orange crystals.

[0132]¹H-NMR (100 MHz, CDCl₃): 7.0-8.2 (m, 21H, arom. H), 6.9 (m, 2H,H—C(3)), 2.4 (s, 3H, CH₃), 2.0 (s, 3H, CH₃), 1.3 (s, 3H, CH₃Si). Massspectrum: 690 M⁺, correct decomposition pattern.

EXAMPLE C rac-Dimethylsilandiylbis(4-phenylindenyl)zirconium dichloride(12)

[0133] 1. 3-(2-phenylphenyl)propionic acid (8)

[0134] 93 cm³ (0.61 mmol) of diethyl malonate dissolved in 50 cm³ ofH₂O-free EtOR were added dropwise at room temperature to 14 g (0.61mmol) of sodium in 400 cm³ of H₂O-free EtOH. 150 g (0.61 mmol) of2-phenylbenzyl bromide in 200 cm³ of H₂O-free EtOR were subsequentlyadded dropwise, and the mixture was refluxed for 3 hours. 102 g (1.83mol) of KOH dissolved in 150 cm³ of H₂O were added at room temperature,and the mixture was refluxed for a further 4 hours. The solvent wasremoved in vacuo, H₂O was added to the residue until the latterdissolved completely, and the mixture was acidified to pH 1 by means ofconcentrated aqueous HCl. The precipitate which formed was filtered offwith suction, dried and heated at 130° C. for 1 hour, giving 112 g (81%)of 8 as a viscous oil.

[0135]¹H-NMR (100 MHz, CDCl₃): 9.1 (s, 1H, COOH), 6.9-7.5 (m, 9H, arom.H), 2.3-3.0 (m, 4H, 2CH₂).

[0136] 2. 4-Phenyl-1-indanone (9)

[0137] A solution of 102 g (0.45 mol) of 8 in 37 cm³ (0.5 mol) ofthionyl chloride was stirred at room temperature for 18 hours. Excessthionyl chloride was removed at 10 mbar, and the oily residue was freedfrom adhering residues of thionyl chloride by repeated dissolution in100 cm³ of toluene in each case and stripping off the toluene in vacuo.

[0138] The acid chloride was taken up in 200 cm³ of toluene and addeddropwise at 10° C. to a suspension of 72 g (0.54 mol) of AlCl₃ in 1000cm³ of toluene. The reaction mixture was heated at 80° C. for 1 hour,poured into 1000 g of ice and acidified to pH 1 by means of concentratedaqueous HCl.

[0139] The organic phase was separated off, and the aqueous phase wasthen extracted 3 times with 200 cm³ of Et₂O in each case. The combinedorganic phases were washed with saturated aqueous NaHCO, solution andsaturated aqueous NaCl solution and subsequently dried (MgSO₄), giving96 g (96%) of 9, which was reacted further without further purification.

[0140]¹H-NMR (100 MHz, CDCl₃): 6.9-7.5 (m, 8H, arom. H), 2.5-3.4 (m, 4H,2CH₂).

[0141] 3. 7-Phenylindene (10)

[0142] 23 g (0.62 mol) of NaBH, were added in portions at 0° C. to asolution of 86 g (0.41 mol) of 9 in 300 cm³ of THF/methanol 2:1. Thereaction mixture was stirred at room temperature for 18 hours and pouredinto 300 g of ice, concentrated aqueous HCl was added to pH 1, and themixture was extracted a number of times with Et₂O. The combined organicphases were washed with saturated aqueous NaHCO₃ solution and saturatedaqueous NaCl solution, dried (MgSO₄) and freed from solvent in vacuo.

[0143] The crude product was taken up in 1000 cm³ of toluene, 4.5 g ofp-toluenesulfonic acid were added, the reaction mixture was refluxed for2 hours on a water separator and washed three times with 250 cm³ ofsaturated aqueous NaHCO₃ solution, and the solvent was removed in vacuo.Distillation at 0.1 mbar gave, at 96-108° C., 33 g (41%) of 10 as acolorless oil.

[0144]¹H-NMR (100 MHz, CDCl₃): 7.1-7.7 (m, 8H, arom. H), 6.9 and 6.5(2m, 2H, CH), 3.5 (m, 2H, CH₂).

[0145] 4. Dimethylbis(4-phenylindenyl)silane (11)

[0146] 18.7 cm³ (50 mmol) of a 20% strength solution of butyllithium intoluene were added at room temperature to a solution of 10 g (50 mmol)of 10 in 100 cm³ of H₂O- and O₂-free toluene and 5 ml of H₂O- andO₂-free THF, and the mixture was heated at 80° C. for 2 hours. Theyellow suspension was subsequently cooled to 0° C., and 3.2 g (25 mmol)of dimethyldichlorosilane were added. The reaction mixture was heated at80° C. for a further 1 hour and subsequently washed with 50 cm³ of H₂O.The solvent was removed in vacuo, and the residue was recrystallizedfrom heptane at −20° C., giving 6.7 g (62%) of 11 as colorless crystals(m.p. 109-110° C.).

[0147]¹H-NMR (100 MHz, CDCl₃): 7.0-7.7 (m, 18H, arom. H and H—C(3)), 6.8(dd, 2H, H—C(2)), 3.8 (m, 2H, H—C(1)), −0.2, (8, 6H, CH₃Si).

[0148] 5. rac-Dimethylsilanediylbis(4-phenylindenyl)zirconium dichloride(12)

[0149] 12 cm³ (32 mmol) of a 20% strength solution of butyllithium intoluene were added at room temperature under argon to a solution of 6.6g (16 mmol) of 11 in 70 cm³ of H₂O- and O₂-free Et₂O, and the mixturewas subsequently refluxed for 3 hours. The solvent was removed in vacuo,the residue was filtered through a G3 Schlenk frit with 50 ml of H₂O-and O₂-free hexane, washed with 50 ml of H₂O- and O₂-free hexane anddried (0.1 mbar, RT).

[0150] The dilithio salt was added at −78° C. to a suspension of 3.6 g(16 mmol) of zirconium tetrachloride in 80 cm³ of methylene chloride,and the mixture was warmed to room temperature over the course of 18hours with magnetic stirring. The batch was filtered through a G3 frit,and the residue was then extracted in portions with a total of 200 cm³of methylene chloride. The combined filtrates were freed from solvent invacuo and recrystallized from methylene chloride/hexane (1:1). 5.6 g ofthe racemic and meso forms in the ratio 1:1 were obtained. Furtherrecrystallization from methylene chloride gave the racemic complex inthe form of yellow crystals.

[0151]¹H-NMR (100 MHz, CDCl₃): 7.0-7.8 (m, 22 H, arom. H and H—C(3)),6.1 (d, 2H, H—C(2)), 1.1 (s, 6H, CH₃Si). Mass spectrum: 598 M⁺, correctdecomposition pattern.

EXAMPLE D rac-Dimethylsilanediylbis(2-ethyl-4-phenylindenyl)zirconiumdichloride (17)

[0152] 1. (±)-2-(2-phenylbenzyl)butyric acid (13)

[0153] 188 g (1 mol) of diethyl ethylmalonate dissolved in 100 cm³ ofH₂O-free EtOH are added dropwise at room temperature to 23 g (1 mol) ofsodium in 400 cm³ of H₂O-free EtOE. 247 g (1 mol) of 2-phenylbenzylbromide in 300 cm³ of H₂O-free EtOH were subsequently added dropwise,and the mixture was refluxed for 3 hours. 170 g (3 mol) of KOH dissolvedin 300 cm³ of H₂O were added at room temperature, and the mixture wasrefluxed for a further 4 hours. The solvent was removed in vacuo, H₂Owas added to the residue until the latter had dissolved completely, andthe mixture was subsequently acidified to pH 1 by means of concentratedaqueous HCl. The precipitate which formed was filtered off with suction,dried and heated at 130° C. for 1 hour, giving 236 g (93%) of 13 as aviscous oil.

[0154]¹H-NMR (100 MHz, CDCl₃): 10.3 (s, 1H, COOH), 7.0-7.3 (m, 9H, arom.H), 2.5-3.0 (m, 3H, CH and CH₂), 1.5-1.9 (m, 2H, CH₂), 0.9 (t, 3H, CH₃).

[0155] 2. (±)-2-Ethyl-4-phenyl-1-indanone (14)

[0156] A solution of 236 g (0.93 mol) of 13 in 81 cm³ (1.2 mol) ofthionyl chloride was stirred at room temperature for 18 hours. Excessthionyl chloride was removed at 10 mbar and the oily residue was freedfrom adhering residues of thionyl chloride by repeated dissolution in200 cm³ of toluene in each case and stripping off in vacuo.

[0157] The acid chloride was taken up in 400 cm³ of toluene and addeddropwise at 10° C. to a suspension of 133 g (1.0 mol) of AlCl₃ in 2000cm³ of toluene. The reaction mixture was heated at 80° C. for 1 hour,poured into 2000 g of ice and acidified to pH 1 by means of concentratedaqueous HCl. The organic phase was separated off, and the aqueous phasewas then extracted three times with 200 cm³ of Et₂O in each case. Thecombined organic phases were washed with saturated aqueous NaHCO₃solution and saturated aqueous NaCl solution and subsequently dried(MgSO₄), giving 187 g (85%) of 14, which was reacted further withoutfurther purification.

[0158]¹H-NMR (100 MHz, CDCl₃): 7.0-7.8 (m, 8H, arom. H), 3.1-3.4 (m, 1H,H—C(3)), 2.5-2.9 (m, 2H, H—C(2)) and H—C(3)), 1.3-2.0 (m, 2H, CH₂), 0.9(t, 3H, CH₃).

[0159] 3. 2-Ethyl-7-phenylindene (15)

[0160] 8 g (0.21 mol) of NaBH, were added in portions at 0° C. to asolution of 50 g (0.21 mol) of 14 in 600 cm³ of THF/methanol 2:1, thereaction mixture was stirred at room temperature for 18 hours and pouredinto 600 g of ice, concentrated aqueous HCl was added to pH 1, and themixture was extracted a number of times with Et₂O. The combined organicphases were washed with saturated aqueous NaHCO₃ solution and saturatedaqueous NaCl solution and subsequently dried (MgSO₄).

[0161] The crude product was taken up in 1000 cm³ of toluene, 4.5 g ofp-toluenesulfonic acid were added, the reaction mixture was refluxed for2 hours on a water separator and washed 3 times with 250 cm³ ofsaturated aqueous NaHCO₃ solution, and the solvent was removed in vacuo.Distillation at 0.1 mbar gave, at 135° C., 33 g (72%) of 15 as acolorless oil.

[0162]¹H-NMR (100 MHz, CDCl₃): 7.0-7.5 (m, 8H, arom. H) 6.5 (m, 1H, CH),3.2 (m, 2H, CH₂), 2.5 (dq, 2H, CH₂), 1.1 (t, 3H, CH₃).

[0163] 3. Dimethylbis(2-ethyl-4-phenylindenyl)silane (16)

[0164] 29 cm³ (77 mmol) of a 20% strength solution of butyllithium intoluene were added at room temperature to a solution of 17 g (77 mmol)of 15 in 160 cm³ of H₂O- and O₂-free toluene and 8 ml of H₂O- andO₂-free THF, and the mixture was heated at 80° C. for 2 hours. Theyellow suspension was subsequently cooled to 0° C., and 5 g (38 mmol) ofdimethylchlorosilane were added. The reaction mixture was heated at 80°C. for a further 1 hour and subsequently washed with 100 cm³ of H₂O. Thesolvent was removed in vacuo, and the residue was purified bychromatography on 200 g of silica gel (hexane/methylene chloride 9:1),giving 9 g (47%) of 16 as a viscous oil.

[0165]¹H-NMR (100 MHz, CDCl₃): 6.97-7.4 (m, 16H, arom. H), 6.5 (m, 2H,H—C(3)), 3.7 (m, 2H, H—C(1)), 2.4 (m, 4H, CH,), 1.1 (t, 6H, CH₃), −0.1,(s, 6H, CH₃Si).

[0166] 5. rac-Dimethylsilanediylbis(2-ethyl-4-phenylindenyl)zirconiumdichloride (17)

[0167] 8.4 cm³ of 20% strength solution of butyllithium in toluene wereadded at room temperature under argon to a solution of 5.6 g (11 mmol)of 16 in 50 cm³ of H₂O- and O₂-free Et₂O, and the mixture wassubsequently refluxed for 3 hours. The solvent was removed in vacuo, andthe residue was filtered through a G3 Schlenk frit with 50 ml of H₂O-and O₂-free hexane, then washed with 50 ml Of H₂O- and O₂-free hexaneand dried (0.1 mbar, RT).

[0168] The dilithio salt was added at −78° C. to a suspension of 2.5 g(11 mmol) of zirconium tetrachloride in 50 cm³ of methylene chloride,and the mixture was warmed to room temperature over the course of 18hours with magnetic stirring. The batch was filtered through a G3 frit,and the residue was then extracted in portions with a total of 100 cm³of methylene chloride. The combined filtrates were freed from solvent invacuo and recrystallized from toluene/hexane (1:1). 2 g (27%) of theracemic and meso forms in the ratio 1:1 were obtained. Furtherrecrystallization from toluene gave the racemic complex 17 in the formof yellow crystals.

[0169]¹H-NMR (100 MHz, CDCl₃): 6.8-7.7 (m, 16H, arom. H), 6.6 (m, 2H,H—C(3)), 2.3-3.9 (m, 4H, CH₂) 1.0-1.4 (m, 12H, CH₃ and CH₃Si). Massspectrum: 654 M⁺, correct decomposition pattern.

EXAMPLE Erac-Dimethylsilanediylbis(2-methyl-4-(1-naphthyl)indenyl)zirconiumdichloride (24)

[0170] 1. 2-(1-Naphthyl)toluene (18)

[0171] 13.9 g (0.57 mol) of magnesium turnings were covered by 150 ml ofH₂O-free Et₂O, and the Grignard reaction was initiated by means of 5 gof 2-bromotoluene and a few grains of iodine. 93 g (0.57 mol) of1-bromotoluene in 450 ml of H₂O-free Et₂O were subsequently addeddropwise at such a rate that the reaction mixture was kept at the boil.When the addition was complete, boiling was continued until themagnesium had reacted fully.

[0172] The Grignard solution was subsequently added dropwise to asolution of 118 g (0.57 mol) of 1-bromonaphthalene and 3.5 g ofbis(triphenylphosphine)nickel dichloride in 800 cm³ of toluene at such arate that the internal temperature did not exceed 50° C. The mixture wassubsequently refluxed for a further 3 hours, 500 ml of 10% strengthaqueous HCl were added, the phases were separated, and the organic phasewas freed from solvent in vacuo. Filtration through silica gel (hexane)gave 115 g (92%) of 18 as a colorless oil.

[0173]¹H-NMR (100 MHz, CDCl₃): 7.2-8.0 (m, 11H, arom. H), 2.0 (s, 3H,CH₃).

[0174] 2. 2-(1-Naphthyl)benzyl bromide (19)

[0175] 114 g (0.52 mol) of 18 and 103 g (0.58 mol) of N-bromosuccinimidewere dissolved in 2000 cm³ of tetrachloromethane at room temperature, 3g of azobisisobutyronitrile were added, and the mixture was refluxed for4 hours. The succinimide which precipitated was filtered off, thesolvent was removed in vacuo, and the residue was purified by filtrationthrough 1000 g of silica gel (hexane/methylene chloride 9:1), giving 141g (82%) of 19 as a colorless lachrymatory oil.

[0176]¹H-NMR (100 MHz, CDCl₃): 7.1-8.0 (m, 11H, arom. H), 4.2 (q, 2H,CH₂Br).

[0177] 3. (t)-2-(2-(1-naphthyl)benzyl)propionic acid (20)

[0178] 75 g (0.43 mmol) of diethyl methylmalonate dissolved in 50 cm³ ofH₂O-free EtOH were added dropwise at room temperature to 10 g (0.43mmol) of sodium in 100 cm³ of H₂O-free EtOH. 140 g (0.43 mmol) of2-phenylbenzyl bromide in 200 cm³ of H₂O-free EtOH were subsequentlyadded dropwise, and the mixture was refluxed for 3 hours. 85 g (1.3 mol)of KOH dissolved in 100 cm³ Of H₂O were added at room temperature, andthe mixture was refluxed for a further 4 hours. The solvent was removedin vacuo, H₂O was added to the residue until the latter had dissolvedcompletely, and the mixture was acidified to pH 1 by means ofconcentrated aqueous HCl. The precipitate which had formed was filteredoff with suction, dried and heated at 130° C. for 1 hour, giving 96 g(77%) of 20 as a viscous oil.

[0179]¹H-NMR (100 MHz, CDCl₃): 10.1 (s, 1H, COOH), 6.9-8.0 (m, 11H,arom. H) 2.3-3.0 (m, 3H, CH₂ and CH), 0.8 (d, 3H, CH₃).

[0180] 4. (±)-2-Methyl-4-(1-naphthyl)-1-indanone (21)

[0181] A solution of 96 g (0.33 mol) of 20 in 37 cm³ (0.5 mol) ofthionyl chloride was stirred at room temperature for 18 hours. Excessthionyl chloride was removed at 10 mbar, and the oily residue was freedfrom adhering residues of thionyl chloride by repeated dissolution in100 cm³ toluene in each case and stripping off in vacuo.

[0182] The acid chloride was taken up in 200 cm³ of toluene and addeddropwise at 10° C. to a suspension of 44 g (0.33 mol) of AlCl₃ in 1000cm³ of toluene, and the reaction mixture was heated at 80° C. for 3hours, poured into 1000 g of ice and acidified to pH 1 by means ofconcentrated aqueous HCl. The organic phase was separated off, and theaqueous phase was then extracted three times with 200 cm³ of methylenechloride in each case. The combined organic phases were washed withsaturated aqueous NaCl₃ solution and saturated aqueous NaCl solution andsubsequently dried (MgSO₄). Chromatography on 1000 g of silica gel(hexane/methylene chloride) gave 12 g (13%) of 21.

[0183]¹H-NMR (100 MHz, CDCl₃); 7.3-8.0 (m, 10H, arom. H), 2.2-3.2 (m,3H, CH₂ and CH), 1.2 (d, 3H, Cl₃).

[0184] 5. 2-Methyl-7-(1-naphthyl)indene (22)

[0185] 1.3 g (33 mmol) of NABH, were added at 0° C. to a solution of 12g (44 mmol) of 21 in 100 cm³ of THF/methanol 2:1, the reaction mixturewas stirred at room temperature for 18 hours and poured into 100 g ofice, concentrated aqueous HCl was added to pH 1, and the mixture wasextracted a number of times with Et₂O. The combined organic phases werewashed with saturated aqueous NaHCO₃ solution and saturated aqueous NaClsolution and subsequently dried (MgSO₄).

[0186] The crude product was taken up in 200 cm³ of toluene, 0.5 g ofp-toluene sulfonic acid was added, the reaction mixture was refluxed for2 hours on a water separator and washed 3 times with 50 cm³ of saturatedaqueous NaHCO₃ solution, and the solvent was removed in vacuo.Filtration through 200 g of silica gel (hexane/methylene chloride) gave10 g (86%) of 22 as a colorless oil.

[0187]¹H-NMR (100 MHz, CDCl₃): 7.0-8.0 (m, 10H, arom. H), 6.6 (m, 1H,CH), 3.0 (m, 2H, CH₂), 2.0 (m, 3H, CH₃).

[0188] 6. Dimethylbis(2-methyl-4-(1-naphthyl)indenyl)silane (23)

[0189] 14.4 cm³ (50 mmol) of a 20% strength solution of butyllithium intoluene were added at room temperature to a solution of 10 g (38 mmol)of 22 in 100 cm³ of H₂O- and O₂-free toluene and 5 ml of H₂O- andO₂-free THF, and the mixture was heated at 80° C. for 2 hours. Theyellow suspension was subsequently cooled to 0° C., and 2.5 g (19 mmol)of dimethyldichlorosilane were added. The reaction mixture was heated at80° C. for a further 1 hour and subsequently washed with 50 cm³ of H₂O.The solvent was removed in vacuo, and the residue was recrystallizedfrom heptane at −20° C., giving 8.2 g (75%) of 23 as colorless crystals.

[0190]¹H-NMR (100 MHz, CDCl₃): 7.2-8.1 (m, 20H, arom. H), 6.4 (m, 2H,H—C(3)), 4.0 (m, 2H, H—C (1)), −0.1, (8, 6H, CH₃Si).

[0191] 7. rac-Dimethylsilanediylbis(2-methyl-4-(1-naphthyl)indenyl)zirconium dichloride (24)

[0192] 10.5 cm³ of a 20% strength solution of butyllithium in toluenewere added at room temperature under argon to a solution of 8.0 g (14mmol) of 23 in 70 cm³ of H₂O- and O₂-free Et₂O, and the mixture wassubsequently refluxed for 3 hours. The solvent was removed in vacuo, andthe residue was filtered through a G3 Schlenk frit with 50 ml of H₂O-and O₂-free hexane, then washed with 50 ml of H₂O- and O₂-free hexaneand dried (0.1 mbar, RT).

[0193] The dilithio salt was added at −78° C. to a suspension of 3.2 g(14 mmol) of zirconium tetrachloride in 80 cm³ of methylene chloride,and the mixture was warmed to room temperature over the course of 18hours with magnetic stirring. The batch was filtered through a G3 frit,and the residue was then extracted in portions with a total of 400 cm³of methylene chloride. The combined filtrates were freed from solvent invacuo and recrystallized from methylene chloride. 1.5 g (15%) of theracemic and meso forms in the ratio 1:1 were obtained. Furtherrecrystallization from methylene chloride gave the racemic complex inthe form of yellow crystals.

[0194]¹H-NMR (100 MHz, CDCl₃): 7.0-8.0 (m, 22H, arom. H), 6.5 (s, 2H,H—C(3)), 2.2 (s, 6H, CH₃), 1.3 (s, 6H, CH₃Si). Mass spectrum: 729 M⁺,correct decomposition pattern.

EXAMPLE Frac-Dimethylsilanediylbis(2-methyl-4-(2-naphthyl)indenyl)zirconiumdichloride (31)

[0195] 1. 2-(2-Naphthyl)toluene (25)

[0196] 14 g (0.57 mol) of magnesium turnings were covered by 150 ml ofH₂O-free Et₂O, and the Grignard reaction was initiated by means of 5 gof 2-bromotoluene and a few grains of iodine. 95 g (0.58 mol) of1-bromotoluene in 450 ml of H₂O-free Et₂O were subsequently addeddropwise at such a rate that the reaction mixture was kept at the boil.When the addition was complete, boiling was continued until themagnesium had reacted fully.

[0197] The Grignard solution was subsequently added dropwise to asolution of 120 g (0.57 mol) of 2-bromonaphthalene and 3.5 g ofbis(triphenylphosphine)nickel dichloride in 800 cm³ of toluene at such arate that the internal temperature did not exceed 50° C. The mixture wassubsequently refluxed for a further 3 hours, 500 ml of 10% strengthaqueous HCl were added, the phases were separated, and the organic phasewas freed from solvents in vacuo. Filtration through silica gel (hexane)gave 107 g (87%) of 25 as a colorless oil.

[0198]¹H-NMR (100 MHz, CDCl₃): 7.0-7.9 (m, 11H, arom. H), 1.9 (s, 3H,CH₃).

[0199] 2. 2-(2-Naphthyl)benzyl bromide (26)

[0200] 105 g (0.48 mol) of 25 and 90 g (0.5 mol) of N-bromosuccinimidewere dissolved in 2000 cm³ of tetrachloromethane at room temperature, 3g of azobisisobutyronitrile were added, and the mixture was refluxed for4 hours. The succinimide which precipitated was filtered off, thesolvent was removed in vacuo, and the residue was purified by filtrationthrough 1000 g of silica gel (hexane/methylene chloride 9:1), giving 112g (79%) of 26 as a colorless lachrymatory oil.

[0201]¹H-NMR (100 MHz, CDCl₃): 6.9-8.0 (m, 11H, arom. H), 4.1 (s, 2H,CH₂Br).

[0202] 3. (±)-2-(2-(2-naphthyl)benzyl)propionic acid (27)

[0203] 70 g (0.37 mmol) of diethyl methylmalonate dissolved in 50 cm³ ofH₂O-free EtOH were added dropwise at room temperature to 8.5 g (0.37mmol) of sodium in 100 cm³ of H₂O-free EtOH. 110 g (0.37 mmol) of 26 in200 cm³ of H₂O-free EtOH were subsequently added dropwise, and themixture was refluxed for 3 hours. 62 g (1.1 mol) of KOH dissolved in 100cm³ of H₂O were added at room temperature, and the mixture was refluxedfor a further 4 hours. The solvent was removed in vacuo, H₂O was addedto the residue until the latter had dissolved completely, and themixture was acidified to pH 1 by means of concentrated aqueous HCl. Theprecipitate which had formed was filtered off with suction, dried andheated at 130° C. for 1 hour, giving 90 g (84%) of 27 as a viscous oil.

[0204]¹H-NMR (100 MHz, CDCl₃): 10.9 (s, 1H, COOH), 7.0-8.1 (m, 11H,arom. H) 2.3-3.0 (m, 3H, CH₂ and CH), 1.0 (d, 3H, CH₃).

[0205] 4. (±)-2-Methyl-4-(2-naphthyl)-1-indanone (28)

[0206] A solution of 89 g (0.31 mol) of 27 in 37 cm³ (0.5 mol) ofthionyl chloride was stirred at room temperature for 18 hours. Excessthionyl chloride was removed at 10 mbar, and the oily residue was freedfrom adhering residues of thionyl chloride by repeated dissolution in100 cm³ of toluene in each case and stripping off in vacuo. The acidchloride was taken up in 200 cm³ of toluene and added dropwise at 10° C.to a suspension of 44 g (0.33 mol) of AlCl₃ in 1000 cm³ of toluene, andthe reaction mixture was heated at 80° C. for 3 hours, poured into 1000g of ice and acidified to pH 1 by means of concentrated aqueous HCl. Theorganic phase was separated off, and the aqueous phase was thenextracted three times with 200 cm³ of methylene chloride in each case.The combined organic phases were washed with saturated aqueous NaHCO₃solution and saturated aqueous NaCl solution and subsequently dried(MgSO₄). Chromatography on 1000 g of silica gel (hexane/AeOEt) gave 27 g(33%) of 28.

[0207]¹H-NMR (100 MHz, CDCl₃): 7.1-8.0 (m, 10H, arom. H), 2.2-3.3 (m,3H, CH₂ and CH), 1.1 (d, 3H, CH₃).

[0208] 5. 2-Methyl-7-2-naphthyl)indene (29)

[0209] 3.8 g (100 mmol) of NaBH₄ were added at 0° C. to a solution of 27g (100 mmol) of 28 in 200 cm³ of THF/methanol 2:1, the reaction mixturewas stirred at room temperature for 18 hours and poured into 100 g ofice, concentrated aqueous HCl was added to pH 1, and the mixture wasextracted a number of times with Et₂O. The combined organic phases werewashed with saturated aqueous NaHCO₃ solution and saturated aqueous NaClsolution and subsequently dried (MgSO₄).

[0210] The crude product was taken up in 500 cm³ of toluene, 1.5 g ofp-toluene sulfonic acid was added, the reaction mixture was refluxed for2 hours on a water separator and washed 3 times with 50 cm³ of saturatedaqueous NaHCO₃ solution, and the solvent was removed in vacuo.Filtration through 200 g of silica gel (hexane/methylene chloride) gave18.4 g (72%) of 29 as a colorless oil.

[0211]¹H-NMR (100 MHz, CDCl₃): 7.0-8.0 (m, 10H, arom. H), 6.6 (m, 1H,CH), 3.0 (m, 2H, CH₂), 2.0 (m, 3H, CH₃).

[0212] 6. Dimethylbis(2-methyl-4-(2-naphthyl)indenyl)silane (30)

[0213] 26 cm³ (70 mmol) of a 20% strength solution of butyllithium intoluene were added at room temperature to a solution of 18 g (70 mmol)of 29 in 70 cm³ of H₂O- and O₂-free toluene and 4 ml of H₂O- and O₂-freeTHF, and the mixture was heated at 80° C. for 2 hours. The yellowsuspension was subsequently cooled to 0° C., and 4.5 g (35 mmol) ofdimethyldichlorosilane were added. The reaction mixture was heated at80° C. for a further 1 hour and subsequently washed with 50 cm³ of H₂O.The solvent was removed in vacuo, and the residue was recrystallizedfrom heptane at −20° C., giving 10.8 g (54%) of 30 as colorlesscrystals.

[0214]¹H-NMR (100 MHz, CDCl₃): 7.0-8.1 (m, 20H, arom. H), 6.4 (m, 2H,H—C(3)), 4.0 (m, 2H, H—C (1)), −0.1, (s, 6H, CH₃Si).

[0215] 7. rac-Dimethylsilanediylbis(2-methyl-4-(2-naphthyl)indenyl)zirconium dichloride (31)

[0216] 13.6 cm³ of a 20% strength solution of butyllithium in toluenewere added at room temperature under argon to a solution of 10.5 g (18mmol) of 30 in 70 cm³ of H₂O- and O₂-free Et₂O, and the mixture wassubsequently refluxed for 3 hours. The solvent was removed in vacuo, andthe residue was filtered through a G3 Schlenk frit with 50 ml of H₂O-and O₂-free hexane, then washed with 50 ml of H₂O- and O₂-free hexaneand dried (0.1 mbar, RT).

[0217] The dilithio salt was added at −78° C. to a suspension of 4.2 g(18 mmol) of zirconium tetrachloride in 80 cm³ of methylene chloride,and the mixture was warmed to room temperature over the course of 18hours with magnetic stirring. The batch was filtered through a G3 frit,and the residue was then extracted in portions with a total of 400 cm³of methylene chloride. The combined filtrates were freed from solvent invacuo and recrystallized from methylene chloride. 3.1 g (23%) of theracemic and meso forms in the ratio 1:1 were obtained. Furtherrecrystallization from methylene chloride gave the racemic complex inthe form of yellow crystals.

[0218]¹H-NMR (100 MHz, CDCl₃): 7.0-8.0 (m, 22H, arom. H), 6.9 (s, 2H,H—C(3)), 2.2 (s, 6H, CH₃), 1.3 (s, 6H, CH₃Si). Mass spectrum: 729 M⁺,correct decomposition pattern.

EXAMPLE G rac-Ethanediylbis(2-methyl-4-phenylindenyl)zirconiumdichloride (33)

[0219] 1. 1,2-Bis(2-methyl-4-phenylindenyl)ethane (32)

[0220] 90 cm³ (0.24 mol) of a 20% strength solution of butyllithium intoluene were added at room temperature under argon to a solution of 50 g(0.24 mol) of 3 in 500 ml of THF. The mixture was stirred at 60° C. for2 hours, and cooled to −78° C., 22.5 g (0.12 mol) of dibromoethane wereadded, and the mixture was warmed to room temperature over the course of18 hours. The reaction mixture was washed with 50 cm³ of H₂O, thesolvent was removed in vacuo, and the residue was chromatographed on 500g of silica gel (hexane/methylene chloride 9:1), giving 2.5 g (5%) of 32as a yellow oil which solidified slowly at −20° C.

[0221]¹H-NMR (100 MHz, CDCl₃): 7.0-8.1 (m, 20H, arom. H), 6.4 (m, 2H,H—C(3)), 4.0 (m, 2H, H—C (1)), −0.1, (s, 6H, CH₃Si).

[0222] 2. rac-Ethanediylbis(2-methyl-4-phenylindenyl)zirconiumdichloride (33)

[0223] 4 cm³ (10 mmol) of a 20% strength solution of butyllithium intoluene were added at room temperature under argon to a solution of 2.3g (5 mmol) of 32 in 20 ml of H₂O- and O₂-free Et₂O, and the mixture wasrefluxed for 3 hours. The solvent was removed in vacuo, the residue wasfiltered through a G3 Schlenk frit with 30 ml of H₂O- and O₂-freehexane, then washed with 30 ml of H₂O- and O₂-free hexane and dried (0.1mbar, RT).

[0224] The dilithio salt was added at −78° C. to a suspension of 1.2 g(5 mmol) of zirconium tetrachloride in 30 cm³ of methylene chloride, andthe mixture was warmed to a temperature over the course of 18 hours withmagnetic stirring. The batch was filtered through a G3 frit, and theresidue was then extracted in portions with a total of 100 cm³ ofmethylene chloride. The combined filtrates were freed from solvent invacuo and recrystallized from methylene chloride/hexane. 0.5 g (18%) ofthe racemic and meso forms in the ratio 1:1 was obtained. Furtherrecrystallization from toluene gave the racemic complex in the form ofyellow crystals.

[0225]¹H-NMR (100 MHz, CDCl₃): 7.0-7.7 (m, 16H, arom. H), 6.6 (m, 2H,H—C(3)), 3.4-4.1 (m, 4H, H₂C—CH₂), 2.1 (s, 6H, CH₃). Mass spectrum : 598M⁺, correct decomposition pattern.

EXAMPLE E Me₂Si(2-Me-4-Ph-indenyl)₂ZrMe[BPh₄] (35)

[0226] 1.rac-Dimethylsilanediylbis(2-Methyl-4-phenyl-indenyl)dimethylzirconium(34)

[0227] 1 cm³ of a 1.6 M (1.6 mmol) solution of methyllithium in Et₂Owere added at −30° C. to 0.5 g (0.8 mmol) of rac-5 in 10 cm³ of H₂O- andO₂-free Et₂O, and the mixture was stirred at 0° C. for 1 hour. Thesolvent was subsequently removed in vacuo, and the residue was taken upin 20 cm³ of H₂O- and O₂-free hexane and filtered off through a G3 frit,giving 0.34 g (72%) of 34. Mass spectrum : 588 M⁺, correct decompositionpattern.

[0228] 2. Me₂Si(2-Me-4-Ph-Indenyl)₂ZrMe[BPh₄] (35)

[0229] 0.2 g (0.3 mmol) of 34 were added at 0° C. to 0.25 g (mmol) oftributylammonium tetraphenylborate in 0 cm³ of toluene. The mixture waswarmed to 50° C. with stirring and stirred at this temperature for 15minutes. An aliquot portion of the solution was used for thepolymerization.

EXAMPLE 1

[0230] A dry 16 dm³ reactor was first flushed with nitrogen andsubsequently with propylene and filled with 10 dm³ of liquid propylene.30 cm³ of a toluene solution of methylaluminoxane were then added, andthe batch was stirred at 30° C. for 15 minutes.

[0231] In parallel, 1.1 mg of rac-5 were dissolved in 20 cm³ of atoluene solution of methylaluminoxane (27 mmol of Al) and reacted bystanding for 15 minutes. The solution was then introduced into thereactor and heated to the polymerization temperature of 50° C. (4°C./min) by supply of heat, and the polymerization system was kept at 50°C. for 1 hour by cooling. The polymerization was terminated by additionof 20 cm³ of isopropanol. The excess monomer was removed in gas form,and the polymer was dried in vacuo, giving 0.9 kg of polypropylene. Thereactor exhibited thin deposits on the internal wall and stirrer. Thecatalyst activity was 818 kg of PP/g of metallocene×h. VI=905 cm³/g;m.p. 159.4° C.; II=98.8%; mmmm=95.4%; M_(w)=1,100,000 g/mol;M_(w)/M_(n)=2.5.

EXAMPLE 2

[0232] The polymerization of Example 1 was repeated with the differencethat the catalyst used was 0.9 mg of rac-5 and the polymerizationtemperature was 70° C. 1.4 kg of polypropylene were obtained. Thereactor exhibited thick deposits on the internal wall and stirrer.Catalyst activity was 1,555 kg of PP/g of metallocene×h. VI=719 cm³/g;m.p.=157.7° C.

EXAMPLE 3

[0233] 22 cm³ of the suspension of “MAO on SiO₂” (49 mmol of Al) wasintroduced under argon into a G3 Schlenk frit, and a solution of 4.5 mgof rac-5 in 10 cm³ of toluene (7.2 μmol of Zr) was added. The reactionmixture was stirred at room temperature for 30 minutes, with aspontaneous color change to red gradually fading. The mixture wassubsequently filtered, and the solid was washed 3 times with 10 cm³ ofhexane. The hexane-moist filter residue which remained was resuspendedin 20 cm³ of hexane for the polymerization.

[0234] In parallel, a dry 16 dm³ reactor was flushed first with nitrogenand subsequently with propylene and filled with 10 dm³ of liquidpropylene. 3 cm³ of triisobutylaluminum (pure, 12 mmol) were thendiluted with 30 cm³ of hexane and introduced into the reactor and thebatch was stirred at 30° C. for 15 minutes. A catalyst suspension wassubsequently introduced into the reactor and heated to thepolymerization temperature of 50° C. (4° C./min), and the polymerizationsystem was kept at 50° C. for 1 hour by cooling. Polymerization wasterminated by addition of 20 cm³ of isopropanol. The excess monomer wasremoved in gas form, and the polymer was dried in vacuo. 300 g ofpolypropylene powder were obtained. The reactor exhibited no deposits onthe internal wall or stirrer. The catalyst activity was 67 kg of PP/g ofmetallocene×h. VI=1380 cm³/g; m.p.=156° C.

EXAMPLE 4

[0235] The synthesis of the supported catalyst system from Example 3 wasrepeated with the difference that 13 cm³ (29 mmol of Al) of thesuspension “MAO on SiO₂” and 1.8 mg of rac-5 (2.9 μmol of Zr) were used.

[0236] The polymerization was carried out analogously to Example 3 at70° C. 420 g of polypropylene powder were obtained. The reactorexhibited no deposits on the internal wall or stirrer. The catalystactivity was 233 kg of PP/g of metallocene×h. VI=787 cm³/g; m.p.=149.5°C.

EXAMPLE 5

[0237] The synthesis of the supported catalyst system from Example 3 wasrepeated with the difference that 150 cm³ (335 mmol of Al) of thesuspension “MAO on SiO₂” and 44.2 mg of rac-5 (70.3 μmol of Zr) wereused and the reaction mixture was stirred at room temperature for 60minutes. The solid was subsequently filtered off and washed 3 times with50 cm³ of hexane. The hexane-moist filter residue which remained wasdried in vacuo to give a free-flowing, pale pink powder. 33.3 g ofsupported, dry catalyst were obtained.

[0238] For the polymerization, 2.98 g of this dry catalyst (4 mg=6.3μmol of Zr) were resuspended in 20 cm³ of hexane.

[0239] The polymerization was carried out analogously to Example 3 at70° C. 1.05 kg of polypropylene powder were obtained. The reactorexhibited no deposits on the internal wall or stirrer. The catalystactivity was 263 kg of PP/g of metallocene×h. VI=944 cm³/g; m.p.=156° C.

EXAMPLE 6

[0240] A dry 1.5 dm³ reactor was flushed with N₂ and filled at 20° C.with 750 cm³ of a benzine cut with the boiling range 100-120° C. fromwhich the aromatic compounds had been removed (“®Exxsol 100/120”). Thegas space of the reactor was then flushed free of nitrogen by injecting8 bar of propylene and releasing the pressure, and repeating thisprocedure four times. 3.75 cm³ of a toluene solution ofmethylaluminoxane (10% by weight of MAO) were then added. The reactorcontents were then heated to 30° C. over the course of 15 minutes withstirring, and the overall pressure was set at 8 bar by addition ofpropylene at a stirring rate of 500 rpm.

[0241] In parallel, 0.1 mg of rac-5 were dissolved in 1.25 cm³ of atoluene solution of methylaluminoxane and reacted fully by standing for15 minutes. The solution was then introduced into the reactor, and thepolymerization system was heated to a temperature of 50° C. and kept atthis temperature for 1 hour by appropriate cooling. The pressure waskept at 8 bar during this time by appropriate supply of propylene, thereaction was then terminated by addition of 2 cm³ of isopropanol, andthe polymer was filtered off and dried in vacuo.

[0242] 16 g of polypropylene were obtained. The reactor exhibiteddeposits on the internal wall and stirrer. The catalyst activity(CTY_(red)) was 20 kg of PP/g of metallocene×h×bar. VI=833 cm³/g; m.p.=159° C.

EXAMPLE 7

[0243] The polymerization of Example 6 was repeated with the differencethat the polymerization temperature was 60° C.

[0244] 35 g of polypropylene were obtained. The reactor exhibiteddeposits on the internal wall and stirrer. The catalyst activity(CTY_(red)) was 44 kg of PP/g of metallocene×h×bar. VI=484 cm³/g;m.p.=159° C.

EXAMPLE 8

[0245] The polymerization from Example 6 was repeated with thedifference that the polymerization temperature was 70° C.

[0246] 88 g of polypropylene were obtained. The reactor exhibiteddeposits on the internal wall and stirrer. The catalyst activity(CTY_(red)) was 110 kg of PP/g of metallocene×h×bar. VI=414 cm³/g;m.p.=159° C.

EXAMPLES 9-12

[0247] The procedure was as in Example 2. However, hydrogen was meteredin before the filling with liquid propylene: Dm²(s.t.) Metalloceneactivity VI Example of H₂ [kg of PP/g of Met × h] [cm³/g] 9 1.5 1640 49510 3 1590 212 11 4.5 1720 142 12 200 1580 17

[0248] Examples 9-12 demonstrate the good hydrogen utilization of themetallocene according to the invention. Molecular weight regulation intothe wax region (see Example 12) is possible.

EXAMPLE 13

[0249] The procedure was as in Example 3. However, 0.2 bar of hydrogenwas injected into the reactor before addition of the catalyst, and thepolymerization temperature was 60° C. However, ethylene was metered inat a uniform rate during the polymerization. In total. 12 g of ethylenewere introduced into the reactor. 0.4 kg of ethylene-copolymer wereobtained. The metallocene activity was 88 kg of copolymer/g ofmetallocene×h. The ethylene content of the polymer was 2.4% by weight,and the ethylene was predominantly incorporated as isolated units.VI=200 cm³/g; melting point 143° C.

EXAMPLE 14

[0250] The procedure was as in Example 13. However, a total of 34 g ofethylene were metered in during polymerization. 0.38 kg ofethylene-propylene copolymer containing 7% by weight of ethylene wasobtained. VI=120 cm³; melting point 121° C.

EXAMPLE 15

[0251] The procedure was as in Example 4. However, 4 g of ethylene weremetered in during the polymerization and 0.1 bar of hydrogen wasinjected before the polymerization. 0.52 kg of ethylene-propylenecopolymer were obtained. The metallocene activity was 286 kg ofcopolymer/g of metallocene×h. The ethylene content of the polymer was6.1% by weight, and the majority of the ethylene was incorporated asisolated units. VI=150 cm³/g; melting point 116° C.

EXAMPLE 16

[0252] A dry 150 dm³ reactor was flushed with nitrogen and filled at 20°C. with 80 dm³ of a benzine cut having the boiling range of 100-120° C.from which the aromatic compounds had been removed. The gas space wasthen flushed free of nitrogen by injecting 2 bar of propylene andreleasing the pressure, and repeating this procedure four times. After50 l of liquid propylene had been added, 64 cm³ of a toluene solution ofmethylaluminoxane (corresponding to 100 mmol of Al, molecular weight1080 g/mol according to cryoscopic determination) were added, and thereactor contents were heated to 50° C. A hydrogen content of 2.0% wasestablished in the gas space of the reactor by metering in hydrogen andwas later kept constant during the 1st polymerization step by subsequentmetering in.

[0253] 9.8 mg of rac-7 were dissolved in 32 ml of the toluene solutionof methylaluminoxane (corresponding to 50 mmol of Al) and wereintroduced into the reactor after 15 minutes. The polymerization wasthen carried out in a 1st polymerization step for 5 hours at 50° C. Thegaseous components were then removed at a reactor pressure of 3 bar, and2000 g of ethylene gas were fed in. The reactor pressure increased to 8bar during this operation, and the polymerization was continued for afurther 14 hours at 40° C. before the reaction was terminated by meansof CO₂ gas.

[0254] 18.6 kg of block copolymer were obtained, corresponding to ametallocene activity of 99.9 kg of copolymer/g of metallocene×h. VI=230cm³/g; MFI (230/5)=11 dg/min, MFI (230/2.16)=3.7 dg/min; melting pointof the polymer in the 1st polymerization step: 159° C., glass transitiontemperature of the polymer in the 2nd polymerization step: −38° C. Theblock copolymer contained 5% of ethylene. Fractionation of the productgave the following composition: 69% by weight of homopolymer, 31% byweight of copolymer, the copolymer having an ethylene content of 15% byweight, and the mean C₂ block length was 2.2.

EXAMPLE 16a

[0255] The procedure was as in Example 16.

[0256] 3 mg of rac-24 were dissolved in 32 ml of the toluene solution ofmethylaluminoxane (corresponding to 50 mmol of Al) and were introducedinto the reactor after 15 minutes. The polymerization was then carriedout in a 1st polymerization step for 2.5 hours at 50° C. The gaseouscomponents were then removed at a reactor pressure of 3 bar, and 3000 gof ethylene gas were fed in. The reactor pressure increased to 8 barduring this operation, and the polymerization was continued for afurther 8 hours at 40° C. before the reaction was terminated by means ofCO₂ gas.

[0257] 16.5 kg of block copolymer were obtained, corresponding to ametallocene activity of 524 kg of copolymer/g of metallocene×h. VI=480cm³/g; MFI (230/5)=2 dg/min, melting point of the polymer in the 1stpolymerization step: 162° C., glass transition temperature of thepolymer in the 2nd polymerization step: −54° C. The block copolymercontained 15% of ethylene.

EXAMPLE 17

[0258] The procedure was as in Example 1, but 12.5 mg of metallocenerac-7 were used. 1.5 kg of polypropylene were obtained; the metalloceneactivity was 120 kg of PP/g of metallocene×h. VI=1050 cm³/g; meltingpoint 159° C.

EXAMPLE 18

[0259] The procedure was as in Example 2, but 4.1 mg of metallocenerac-7 were used. 1.3 kg of polypropylene were obtained; the metalloceneactivity was 317 kg of PP/g of metallocene×h. VI=555 cm³/g; meltingpoint 157° C.

COMPARATIVE EXAMPLE A

[0260] The procedure was as in Example 1, but 12.5 mg ofrac-phenyl(methyl)silanediylbis(2-methyl-1-indenyl)zirconium dichloridewere used. 1.35 kg of polypropylene were obtained; the metalloceneactivity was 108 kg of PP/g of metallocene×h. VI=1050 cm³/gl; meltingpoint 149° C.

COMPARATIVE EXAMPLE B

[0261] The procedure was as in Example 1, but 12.5 mg of rac-phenyl(methyl) silanediylbis (1-indenyl) zirconium dichloride were used. 0.28kg of polypropylene were obtained; the metallocene activity was 22.4 kgof PP/g of metallocene×h. VI=74 cm³/gl; melting point 141° C.

EXAMPLE 19

[0262] The procedure was as in Example 1, but 3.3 mg of 24 were used.0.78 kg of polypropylene were obtained; metallocene activity was 237 kgof PP/g of metallocene×h. VI=1700 cm³/g; melting point 163° C.,M_(w)=2.1×10⁶ g/mol, MFI 230/21.6 1 dg/min; M_(w)/M_(n)=2.1.

EXAMPLE 19a

[0263] The procedure was as in Example 2, but 1.0 mg of rac-24 wereused. 1.2 kg of polypropylene were obtained. The metallocene activitywas 1200 kg of PP/g of metallocene×h. VI=1100 cm³/g. Melting point=161°C.

EXAMPLE 20

[0264] The procedure was as in Example 1; however the polymerizationtemperature was 40° C. 6.0 mg of 17 were used. 1.95 kg of polypropylenewere obtained; the metallocene activity was 325 kg of PP/g ofmetallocene×h. VI=1320 cm³/g; melting point 162° C., M_(w)=1.79×10⁶g/mol, M_(w)/M_(n)2.3.

COMPARATIVE EXAMPLE C

[0265] The procedure was as in Example 20, but the conventionalmetallocene rac-dimethylsilanediylbis(2-ethyl-1-indenyl)zirconiumdichloride was used. 0.374 kg of polypropylene were obtained; themetallocene activity was 62.3 kg of PP/g of metallocene×h. VI=398 cm³/g;melting point 147° C., M_(w)=450,000 g/mol, M_(w)/M_(n)=2.5.

EXAMPLE 21

[0266] The procedure was as in Example 1, but 5.2 mg of 31 were used.1.67 kg of polypropylene were obtained; the metallocene activity was 321kg of PP/g of metallocene×h. VI=980 cm³/g; melting point 158° C.

EXAMPLE 22

[0267] The procedure was as in Example 1, but the polymerization wascarried out at 30° C. and 3.7 mg of 33 were used. 0.35 kg ofpolypropylene were obtained; the metallocene activity was 94 kg of PP/gof metallocene×h. VI=440 cm³/g; melting point 153° C.

EXAMPLE 23

[0268] A dry 16 dm³ reactor was flushed with propylene and filled with10 dm³ of liquid propylene. 1.1 cm³ of the reaction product from H.2(corresponding to 7.5 mg of 34) were then dissolved in 20 cm³ of tolueneand introduced into the reactor at 30° C. The reactor was heated to 50°C. (10° C./min) and the polymerization system was kept at thistemperature for 1 hour by cooling. The polymerization was terminated byaddition of CO₂ gas. The excess monomer was removed in gas form, and thepolymer was dried in vacuo at 80° C. 2.45 kg of polypropylene wereobtained. VI=875 cm³/g; melting point 160° C.

EXAMPLE 24

[0269] A dry 16 dm³ reactor was flushed with nitrogen and filled at 20°C. with 10 dm³ of a benzine cut having the boiling range 100-120° C.from which the aromatic compounds had been removed. The gas space of thereactor was then flushed free of nitrogen by injecting 2 bar of ethyleneand releasing the pressure and repeating this operation 4 times. 30 cm³of a toluene solution of methylaluminoxane (corresponding to 45 mmol ofAl, molecular weight 700 g/mol according to cryoscopic determination)were then added. The reactor contents were heated to 30° C. over thecourse of 15 minutes with stirring, and the overall pressure was set at5 bar by addition of ethylene at a stirring rate of 250 rpm.

[0270] In parallel, 3.2 g of 12 were dissolved in 20 cm³ of a toluenesolution of methylaluminoxane and were preactivated by standing for 15minutes. The solution was then introduced into the reactor, and thepolymerization system was heated to a temperature of 50° C. and kept atthis temperature for 4 hours by appropriate cooling. The overallpressure was kept at 5 bar during this time by a appropriate supply ofethylene.

[0271] The polymerization was terminated by addition of 20 ml ofisopropanol, and the polymer was filtered off and dried in vacuo. 0.7 kgof polyethylene were obtained. VI=690 cm³/g.

EXAMPLE 25

[0272] The procedure of Example 24 was followed. In contrast to Example23, 1.8 mg of rac-7 were employed, and the polymerization system washeated to 70° C. and kept at this temperature for 1 hour. 0.9 kg ofpolyethylene were obtained. VI=730 cm³/g.

EXAMPLE 26

[0273] 15 g of “F-MAO on SiO₂” (111 mmol of Al) were suspended in 100cm³ of toluene in a stirrable vessel and cooled to −20° C. At the sametime, 155 mg (0.246 mmol) of rac-5 were dissolved in 75 cm³ of tolueneand added dropwise to this suspension over the course of 30 minutes. Themixture was slowly warmed to room temperature with stirring, thesuspension taking on a red color. The mixture was subsequently stirredat 80° C. for 1 hour, cooled to room temperature and filtered, and thesolid was washed 3 times with 100 cm³ of toluene in each case and oncewith 100 cm³ of hexane. The filtrate was red. The hexane-moist filterresidue which remained was dried in vacuo, giving 13.2 g offree-flowing, pale red, supported catalyst. Analysis gave a content of3.2 mg of zirconocene per gram of catalyst.

[0274] Polymerization: For the polymerization, 2.08 g of the catalystwere suspended in 50 cm³ of a benzine cut having the boiling range of100-120° C. from which the aromatic compounds had been removed. Thepolymerization was carried out analogously to Example 3 at 60° C. 1100 gof polypropylene powder were obtained. The reactor exhibited no depositson the internal wall or stirrer. Activity=165 kg of PP/(g ofmetallocene×h). VI=1100 cm³/g. Melting point=153° C.; M_(w)=1,485,000;M_(w)/M_(n)=3.2; MFI 230/5=0.1 dg/min; BD=440 g/dm³.

EXAMPLE 27

[0275] 1.31 g of the catalyst from Example 26 were suspended in 50 cm³of a benzine cut having the boiling range of 100-120° C. from which thearomatic compounds had been removed. The polymerization was carried outanalogously to Example 3 at 70° C. 1300 g of polypropylene powder wereobtained. The reactor exhibited no deposits on the internal wall orstirrer. Activity=310 kg of PP/(g of metallocene×h). VI=892 cm^(3/)g;melting point=150° C., M_(w)=1,290,000; M_(w)/M_(n)=3.0; BD=410 g/dm³.

EXAMPLE 28

[0276] The supporting procedure from Example 26 was repeated with thedifference that 0.845 g of rac-5 dissolved in 500 cm³ of toluene werereacted with 90 g of “F-MAO on SiO₂” and suspended in 500 cm³ oftoluene. 84 g of red, pulverulent catalyst were obtained. Analysis gavea content of 9 mg of metallocene per gram of solid, and the red filtratecontained 13 mg of zirconium.

[0277] Polymerization: 1.1 g of the supported catalyst were suspended in50 ml of a benzine cut having a boiling range of 100-120° C. from whichthe aromatic compounds had been removed. The polymerization was carriedout analogously to Example 3 at 70° C. 2850 g of polypropylene powderwere obtained. The reactor exhibited no deposits on the internal wall orstirrer. Activity=288 kg of PP/(g of metallocene×h); VI=638 cm³/g;melting point=150° C.; MFI 230/5=0.5 dg/min; BD=410 g/dm³.

EXAMPLE 29

[0278] A microporous polypropylene powder (AKZO) having a particle sizeof smaller than 100 μm was freed from impurities by extraction withtoluene in a Soxhlet extractor under inert conditions and subsequentlywashed with 20% strength by weight of trimethylaluminum solution intoluene and dried in vacuo. In parallel, 51.1 mg of rac-5 were dissolvedin 40 cm³ of a toluene solution of methylaluminoxane and reacted fullyby standing for 15 minutes. 16.5 g of the PP powder were metered in, andthe gas in the pores of the support and some of the solvent were removedby briefly applying a vacuum, and the catalyst solution was absorbedfully. Vigorous shaking of the reaction vessel gave 46 g of homogeneous,finely divided and free-flowing red powder. 10 g of the supportedcatalyst powder were prepolymerized for 30 minutes with ethylene underinert conditions in a rotary evaporator. The ethylene excess pressurewas kept constant at 0.1 bar by means of a pressure-regulation valve,and the mixing of the catalyst powder was achieved by continuousrotation of the reaction vessel with cooling at 0° C. 12 g ofprepolymerized catalyst were obtained.

[0279] Polymerization: 4.6 g of the supported, prepolymerized catalystwere suspended in 50 cm³ of a benzine cut having the boiling range100-120° C. from which the aromatic compounds had been removed.Polymerization was carried out analogously to Example 3 at 70° C. 250 gof polypropylene powder were obtained. The reactor exhibited no depositson the internal wall or stirrer, and the mean particle size was 1,000μm. Activity=59 kg of PP/(g of metallocene×h); VI=734 cm³/g. Meltingpoint=152° C.; BD=390 g/dm³.

EXAMPLE 30

[0280] 1 g of the supported, non-prepolymerized catalyst from Example 29was suspended in 50 cm³ of n-decane for the polymerization. Thepolymerization was carried out analogously to Example 3 at 70° C. 600 gof polypropylene were obtained. The reactor exhibited thin deposits onthe internal wall and stirrer, and the mean particle diameter was>2000μm. Activity=540 kg of PP/(g of metallocene×h); VI=1400 cm³/g; meltingpoint=157.7° C.; BD=280 g/dm³.

1. A compound of formula I

in which M¹ is a metal from group IVb, Vb or VIb of the Periodic Table,R¹ and R² are identical or different and are a hydrogen atom, aC₁-C₁₀-alkyl group, a C₁-C₁₀-alkoxy group, a C₆-C₁₀-aryl group, aC₆-C₁₀-aryloxy group, a C₂-C₁₀-alkenyl group, a C₇-C₄₀-arylalkyl group,a C₇-C₄₀-alkylaryl group, a C₈-C₄₀-arylalkenyl group, an OH group or ahalogen atom, the radicals R³ are identical or different and are ahydrogen atom, a halogen atom, a C₁-C₁₀-alkyl group, which may behalogenated, a C₆-C₁₀-aryl group, an —NR¹⁶ ₂, —SR¹⁶, —OSiR¹⁶ ₃, —SiR¹⁶ ₃or —PR¹⁶ ₂ radical, in which R¹⁶ is a halogen atom, a C₁-C₁₀-alkyl groupor a C₆-C₁₀-aryl group, R⁴ to R¹² are identical or different and are asdefined for R³, or adjacent radicals R⁴ to R¹², together with the atomsconnecting them, form one or more aromatic or aliphatic rings, or theradicals R⁵ and R⁸ or R¹², together with the atoms connecting them, forman aromatic or aliphatic ring, R¹³ is

═BR¹⁴, ═AIR¹⁴, —Ge—, —O—, O—S—, ═SO, ═SO₂, ═NR¹⁴, ═CO, ═PR¹⁴ or═P(O)R¹⁴, where R¹⁴ and R¹⁵ are identical or different and are ahydrogen atom, a halogen atom, a C₁-C₁₀-alkyl group, aC₁-C₁₀-fluoroalkyl group, a C₁-C₁₀-alkoxy group, a C₆-C₁₀-aryl group, aC₆-C₁₀-fluoroaryl group, a C₆-C₁₀-aryloxy group, a C₂-C₁₀-alkenyl group,a C₇-C₄₀-arylalkyl group, a C₇-C₄₀-alkylaryl group or aC₈-C₄₀-arylalkenyl group, or R¹⁴ and R¹⁵, in each case together withatoms connecting them, form one or more rings, and M² is silicon,germanium or tin.
 2. A compound of the formula I as claimed in claim 1 ,wherein, in the formula I, M¹ is zirconium or hafnium, R¹ and R² areidentical and are a C₁-C₃-alkyl group or a halogen atom, the radicals R³are identical and are a C₁-C₄-alkyl group R⁴ to R¹² are identical ordifferent and are hydrogen or a C₁-C₄-alkyl group, and R¹³ is

where M² is silicon or germanium and R¹⁴ and R¹⁵ are identical ordifferent and are a C₁-C₄-alkyl group or a C₄-C₁₀-aryl group.
 3. Acompound of the formula I as claimed in claim 1 , wherein, in theformula I, R⁴ and R⁷ are hydrogen, and R⁵, R⁶ and R⁸ to R¹² areidentical or different and are hydrogen or a C₁-C₄-alkyl group.
 4. Acompound of the formula I as claimed in claim 1 , wherein, in formula I,M¹ is zirconium, R¹ and R² are identical and are chlorine, the radicalsR³ are identical and are a C₁-C₄-alkyl group, R⁴ and R⁷ are hydrogen,R⁵, R⁶ and R⁸ to R¹² are identical or different and are a C₁-C₄-alkylgroup or hydrogen, and R¹³ is

where M² is silicon and R¹⁴ and R¹⁵ are identical or different and are aC₁-C₄-alkyl group or a C₆-C₁₀-aryl group.
 5. A compound of formula I asclaimed in claim 1 , wherein, in the formula I, M¹ is zirconium, R¹ andR² are chlorine, the radicals R³ are methyl or ethyl, R⁴ to R¹² arehydrogen, and R¹³ is

where M² is silicon, and R¹⁴ and R¹⁵ are identical or different and aremethyl, ethyl, n-propyl, i-propyl or phenyl.
 6. A process for thepreparation of an olefin polymer by polymerization or copolymerizationof an olefin of the formula R^(a)—CH═CH—R^(b), in which R^(a) and R^(b)are identical or different and are a hydrogen atom or a hydrocarbonradical having 1 to 14 carbon atoms, or R^(a) and R^(b), together withthe atoms connecting them, can form one or more rings, and at atemperature of from −60 to 200° C., at a pressure of 0.5 to 100 bar, insolution, in suspension or in the gas phase, in the presence of acatalyst formed from a metallocene as transition-metal compound and acocatalyst, wherein the metallocene is a compound of the formula I asclaimed in claim 1 .
 7. The process as claimed in claim 6 , wherein thecocatalyst used is an aluminoxane of the formula IIa for the linear typeand/or of the formula IIb for the cyclic type

where, in the formulae IIa and IIb, the radicals R¹⁷ are identical ordifferent and are a C₁-C₆-alkyl group, a C₆-C₁₈-aryl group, benzyl orhydrogen, and p is an integer from 2 to
 50. 8. The process as claimed inclaim 6 , wherein the cocatalyst used is methylaluminoxane.
 9. Theprocess as claimed in claim 6 , wherein the metallocene of the formula Iis preactivated by means of an aluminoxane of the formula IIa and/or IIbbefore use in the polymerization reaction.
 10. The process as claimed inclaim 6 , wherein a supported polymerization catalyst is employed whichis the product of the reaction of a metallocene of the formula I with asupported organoaluminum compound (cocatalyst).
 11. The process asclaimed in claim 10 , wherein the support material is an oxide ofsilicon and/or of aluminum, and the organoaluminum compound ismethylaluminoxane.
 12. The use of a metallocene of formula I as claimedin claim 1 as a catalyst component in the polymerization orcopolymerization of olefins.